A. Cliffside
Per the “Entering the City” section on page 91.
Add to the description: "Smoke gently floats from several chimneys, mostly in the part of the city east of the river, suggesting perhaps a few hundred inhabitants."
B. Tabaxi and Yuan-Ti ambush
Here they meet two eldery Tabaxi hunters (Hooded Lantern and Copper Bell, use
assassin stats) that introduce themselves by fighting a common foe. They provide vital foreshadowing on a number of topics, so take efforts to make this encounter go well, including fudging the defeat of the snake scouts if necessary.
Here is a
malison scouting the city entrance
in snake form. He's got a backup force of three groups of five
purebloods led by another
malison each.
Either when the snake scout is discovered or when he triggers the ambush, the two Tabaxi start shooting snake people, helping the characters. At least one Yuan-Ti should burst into snakes each round. Even if their contribution won't ultimately matter, Copper Bell's ability should creep and awe the characters sufficiently.
Once the pesky snake people have been dispatched, the Tabaxi have the following to say:
1) We seek honorable death as hunters of the greatest prey.
• I, Hooded Lantern, am here for the King of Feathers. Prophecy tells it will be slain by a mighty warrior in single combat. I'd like to think I am that warrior. Either way, the King shall be the end of me.
• I, Copper Bell, am here for "the Night Snake". I have dreamt it will devour me, and have said farewell to my families to see if it is a true dream. Before that happens, however, I would like to find and use the great treasure, the Navel of the Moon, said to allow you to connect to your distant kin.
(Feel free to play up their defaitism. And play up her promiscuous past, akin to hippie seventies free love, if you like! Nothing freaks out male humans as when you suggest their grandmother is sexually active

)
• Our friend and greatest hunter, Bag of Nails, have slipped into the clouds of the mind, and fears everyone is after him. He used to talk about the Navel of the Moon, but I think it is too late for Bag, who will soon be one with the ancestors himself. We have said our goodbyes. You must respect his mighty Oathbow; once he has set his sight on a prey none has lived. Should you encounter him and live to tell the tale, we ask only that you treat him and his body with respect. He was once our mightiest hunter, and does not deserve a pitiful death.
2) the Yuan-Ti live mostly "across the water" where the palace is. There's quite a lot of them. Most of them worship undead and engage in grisly rituals, but not all of them. We have asked the snake people we have caught; their "king" is somebody called "Ras Nsi". Their "queen" (actually head priestess) is "Fenthaza". And the outcasts, that don't consort with the dead, are led by somebody they call "Kaas-bil".
3) there are images and temples to "old Omu gods" all over the city, that are neither praised Ubtao nor dark snake gods (=the nine trickster gods). We haven't really explored the city, though Bag has moved ahead.
4) We've seen two groups of paleskinned outsiders enter the city recently. First came a strange lot [reference description/picture of Argentate Blades, now caught/insane down the Fane] that were somewhat cordial, then an even stranger lot all dressed up the same and quite unfriendly they were too! It didn't take them long to make enemies with the snake people and boy did they like fireballs! [=Red Wizards, which will have arrived just a few days prior, and are still at large].
Hooded Lantern: replace
Assassin poison with Hunter traits (+2d8 dmg against marked enemy bigger than Hooded Lantern). If you wish, make him have dim eyesight (which should make him get disadvantage, if that ever matters).
Copper Bell: Also
Assassin stats with a poison named "The Calling" (“something I learnt from the elves”), meaning her poison is one a) yuan-ti isn't immune against, and b) if it kills a human (half-orc, half-elf etc) or Yuan-Ti, a swarm of poison snakes bursts forth.
C. Guardhouse with grafitti (original location #1)
Keep grafitti as is. The ambush is moved (and expanded) to B just above.
D. Walled Compound with Orvex (original location #2)
Orvex is caught as described, only add several scores of putrid piles of sludge (zombies fireballed over and over).
Unless ignored or killed off, Orvex can provide info on his masters (Dyrax, Thazma, Voj, Yamoch, and Zagmira) - note how he's unawares of Voj's fate. He makes Dyrax out to be the leader, while Thazma was his "handler".
Change the backstory to the Red Wizards gaining the upper hand, only retreating from the battle when overwhelming numbers of undead that refused to stay dead swamped their position. (Ras Nsi and his guards aren't all that powerful, but somehow his mastery of necromancy is).
Also make sure he mentions "the spy" inside "the fane" as well as a casual mention of their meeting with the "floating rock woman" (=Valindra). The point is for the PCs to know there's something to be gained by cooperating with the Red Wizards, as well as their immense powers and powerful ally.
The Walled Compound was once "druidhome" where nature allies from all over Chult were once welcome.
E. House of Vines (Comp)
Three floors. There's a 20 ft hole in the first floor ceiling, with vines hanging down to allow "easy" access to the second floor without using the crumbling staircases.
Upstairs are 6 comfortable bedrooms, each with a lockable door if you cut away the vines growing everywhere. Plus a "trophy room", where the "assassin nexus" has taken root, a semi-sentient plant structure, who attacks only when someone enters its room (it's currently digesting one of the red wizard mercenaries who fled here).
Third floor: Dining room, kitchens. Each dinner table chair carved as a dinosaur.
Monsters: Use the
shambling mound statistics for the nexus, and add [number of players +1]
assassin vines for its "tentacles" that creep throughout the House of Vines.
Treasure: minor treasure in each of the six bedrooms. Throphy room: Stuffed monsters (eblises, su-monsters, pteramen, grungs, ...) and ornate yklwas mounted on the walls. One is runic and is a +2 Yklwa with the power that its wielder's footsteps becomes that of a dinosaur (of up to huge size).
F. Kubazan (original location #3)
I'll probably keep the sole Froghemoth, only making the pool deeper so it can snatch one PC and force anyone else to dive into the pool*. Also, the party doesn't need the advance warning, so don't have it reveal itself by sticking up its eyestalks.
*) rule you don't have line of sight to the submerged 'hemoth from above the surface.
The puzzle and traps inside are easy, but that's okay. Add a magical gust of wind preventing the heroes from simply jumping across.
G. Pyramid Fruit and Storm (Comp)
Just after entering this complex, a hurricane hits Omu, with rain coming down, the wind blowing hard.
Pyramid fruit was cultivated here (described in the compendium).
A character wandering off on its own, trying a piece of fruit or otherwise shows curiosity has a frightening sight: part of the roof is ripped off and a huge feathered tyrannosaur is looking down on you!
This is actually not the King of Feathers but a powerful vision - make a DC 15 Wisdom save or flee in terror (which, given the storm, allows the DM to subject the character to anything from getting lost to meeting a (real) monster out on the streets.
The hole in the roof is real tho.
Mentioning the storm is just good DMing - the adventure otherwise kind of forgets the weather! Cool idea with King of Feathers stopping by, only I don't want to short-circuit the real combat (at location U), so I'm making this a vision (=illusion) only.
H. Ubtao Shrine
This is an old Ubtao temple, now defaced and derelict. This structure is in worse shape than the nine shrines - there's a huge hole in the roof letting rain and vegetation in. If they root around, they will find one particular find: one headstone inside the ruined inner sanctum has toppled face down - if they lift it, and restore it to its place, and are generally deferential, they can trace its maze with a finger, and lo and behold: each charge will provide a member of the party with "Ubtao's Favor" - the ability to gain the benefits of a long rest when resting for 8 hours as per the regular rules.
There are more such Favors to be found in Omu. This particular shrine contains 1d10 charges, and is then depleted (at least for this adventure). None of the other adventurers have found this one. There are no traps or monsters or treasure here.
I. Shagambi (original location #4)
Hurting the Kamadan cubs makes Shagambi curse you as per Bestow Curse (DC 15).
Inside, "fighting with honor" is key. If the heroes challenge each monster on an "honorable" duel* the puzzle cube can be taken as described. If they gang up to kill off each gladiator as soon as it appears, its spear also crumbles to dust. It should be clear they need the spears. The trap resets next sunrise if they want to try again.
*) like one on one or otherwise as Shagambi (the DM) deems fair; treating their opponents honorably etc
J. Sacrifice of Fire (from #5)
Talk to or fight the Vegepygmies, and Chief Yorb's beloved son Imbok.
K. Fallen Tree (original location #7)
Heh. You're gonna love this one.
Bag of Nails is the greatest Tabaxi hunter that have ever lived. And he's completely nutters. Love his image - it's like a nightmare version of Disney's Prince John! Imagine describing to your characters hearing the whoosh of an arrow, and then see their faces fall when you say "it hits for 20d6 damage" not to mention "as you lose consciousness, you see your own name written on the arrow"
He has divinatory powers that allow him to scribe the character's name on arrows, creating Arrows of Slaying three times per rest. He's ambushing them from across the river 600 ft away. He's even put up a dummy (location c) to draw the party's counterfire (which alerts the Yuan-Ti). He should come really close to one-shotting level 10 characters for that yummy fantasy frikking Vietnam experience
I am planning to use a battlemap here, so characters can indicate where they go and where they look. With an abstract map, it's all to easy to say "I just hide, then I go around and take out the sniper from the back". It should be really difficult to target him, with his ability to move and re-hide after each shot.
Of course, they're about 10th level, and he's alone with "only" 120 hp, so I'm sure they will handle him just fine.
Hopefully they will still gain some respect for the greatest Tabaxi hunter that ever lived, and grant him a proper burial (together with the friends he killed

) just as Copper Bell wished.
Bag of Nails: 120 hp, with "Oathbow"* (advantage at 600 ft range, +3d6 vs mark): one attack at +11 for 20d6 (my approximation = 1d8+3d6+6 dmg plus +4d6 sneak plus 6d10 piercing DC 17 Con save for half) or 40d6 on a critical

Arrows bear target's name (choose three PCs at random).
*) not exact DMG stats
L. Maze Home (Comp)
A dusty derelict house, built with Ubtao's teaching in mind (think of it as a museum). Each room has an engraved maze on a wall, well used. Somebody has been here recently [Red Wizards]
The top floor features a secret maze, accessed by tracing any top floor room maze with your finger. There are four windowless rooms in the interior labyrinth:
1) offerings vault (undisturbed)
Treasure: bejeweled dinosaur claw gauntlets, tyrannosaur hide hooded cape, gold brontosaur figurine (500 gp each).
2) bedroom (rummaged). Sets of fine clothes lie strewn about the floor (10 gp each enough to look like an Omuan Noble).
3) inner sanctum with maze tablet. Ubtao's Favor 1d10 - 5 charges [to account for Red Wizards recharging]
4) storage with nine recently destroyed human remains (zombies defeated by the RW)
M. Adventurers' Camp (original location #9)
Since this location doesn't really provide much more info on Company of the Yellow Banner, I'm repurposing it for "my" adventure party, the Argentate Blades (that you will encounter in the Fane).
Having NPCs writing letters "to the audience" is silly. The Company was here weeks ago - the camp would not have remained out in the open like that.
Anyway. Personally I think the grafitti is enough to establish the company's presence in Omu - the letter (handout 13 that is) is writing the clues on the nose, and your players have likely already all info they need.
Instead, the camp contains enough personal belongings to indicate the Argentate Blades was here, but also enough supplies to indicate they never came back to break camp. [They tried to infiltrate the Fane only to meet with various horrible ends].
N. House of Parrots (Comp)
The lower floor is in a foot of water. The owner had many birds as pets. Now over a hundred parrots live here. One room is full of seeds from floor to roof, and a crack in the door means new food is always spilling out.
When an adventurer enters, the parrots go silently (if not attacked). Anything said will be repeated and learnt by all the parrots in utter unison. This makes the parrots a good warning system - they will start to speak their phrases as soon as anyone sneaks near.
The upper floor is fully inhabitable (if cleaned up; especially if the parrots are confined to downstairs), with an opulent domed lounge, bedrooms with individual privvies.
In the spirit of the original idea of a safe house, I'm having the character who first thinks to actively speak to the parrots gain Ubtao's favor (and his sentence repeated back to him).
O. Finde's Magical Oils and Elixirs
The building looks brand new - suspiciously pristine. The shopkeeper is a heavyset female Minotaur named
Finde. She only accepts payment in platinum coins. Though she just got robbed by an unfriendly girl called Thazma with goggles, a shaved head and several nasty looking body-guards. Finde is friendly and talkative to customers, since if she leaves her shop, she fades away only to wake up next morning without ageing. She asks the heroes if they've come across any good-looking Minotaurs lately.
This means it's not exactly Groundhog Day - time keeps passing outside the shop. Instead she's using this phenomenon to escape hostiles as well as keep from growing old, as she keeps trying to brew a potion that breaks the spell.
She can recount the (ancient) history of Omu, since she has lived through it all. She can point out landmarks, such as Druidhome (=Walled Compound), Foreigner's Steps (with Ambassadors' Homes; magically sealed), the Bazaar, the Bathhouse, and of course the Royal Palace. She doesn't know much about recent affairs (the lich is only “the darkness”, and it was a long time any of the yuan-ti spoke to her)
P. The Bell Tower of the Dinosaur Lord (Comp)
Bad location. Pretty nasty (and cool) trap.
Q. Magic Academy (Comp)
Since there's no actual reason to throw spells around inside the Academy, I will make the Wild Surges "stick" to the characters even as they leave.
The Arcane Steps
Have the characters navigate the maze and climb the stairs individually (two DC 13 Int checks each).
Maze. The first (the one rolling the highest on the first Intelligence check) to solve the maze gains Ubtao's Favor (=long rest), and succeeds automatically on the climb check. The one rolling the lowest (among those who failed) gets to fight the girallons by himself.
Stairs. Since I have plans for the King of Feathers, falling into the magical cloud instead moves your consciousness inside either of the two skeletal familiars. Your body gets teleported to 1st floor as described, but your mind now occupies either a skeletal pseudodragon or a skeletal sprite*. If three or more PCs fall, this happens to the two that rolls the lowest. The others just get teleported back to the first floor (with their minds intact).
*) I'd use the cooler "enhanced" familiars available to warlocks (and not remove any flight ability), as consolation for becoming a familiar...
Don't give out any clues as to how long this effect lasts. It should be up to you - either until the novelty has worn out (after at least one major encounter where the character didn't just hide to avoid all danger), or until the party takes a long rest (which assumes they think to grant the affected character/familiar Ubtao's Favor). Obviously they need to bring along their mindless bodies.
R. I'Jin (original location #10)
Killing the almiraj makes I'Jin curse you as per Bestow Curse (DC 15).
The rule is "don't step on the same animal twice" and the exception is "except for the almirajs". All amirajs need to be stepped on to remove the puzzle cube (no temp hp).
Each square of the mini-labyrinth features a pressure plate (that doesn't do anything except freak out adventurers).
The doors to 10D open only when both doors are opened at the same time (forcing the party to split up, which also freaks out veteran players).
S. Dino-Dragon Inn (Comp) with Chwinga Wagon (original location #11)
I'm envisioning this entire sector to be the "foreigner's quarters".
The wagon is there, per ToA. It's just outside the building described in the compendium as the Dino-Dragon Inn.
Don't use the monster (the assassin vine). Make the crated food magically preserved. Keep the I'Jin maze.
T. Bazaar (original location #15)
Moved here to allow the Bathhouse to occupy the grand structure #15 instead.
The Kobolds need no upgrade.
U. Amphi-theatre (original location #13)
Here's a cool idea, if possibly difficult to pull off successfully: imagine each character approaching to get his own
personal copy of the King of Feathers to fight!!!
The King of Feathers is protected by a mythal prophecy (when the powers that be say "slain in single combat" they really mean it!) of undispellable power.
Each party member enters his own Amphitheatre, his own demiplane.. with his own King to either face or to flee from (good luck with that). As long as they don't interact with King of Feathers, they will only notice “ghosting” in vision and sound (allies will sound slurred and look blurry but they will still "stay together". If they try to hold hands they will realize they're really separated).
When interaction with King of Feathers forces separation of destinies, everyone else (but you and “your” King of Feathers) will fade out like a ghost. This means, if the King chases your friend, you will see a ghost dino chase away, while "the real" Tyrannosaurus will still remain focused entirely on YOU
Interaction between planes like Ethereal Plane – you can see and hear into each of those up to 60 feet away, but can't interact with them, unless using magic. See Invisibility allows you to watch all versions of the entire arena clearly as you'd expect. Magic Missile and Wall of Force will work, etc.
V. Greenhouse (Comp)
Keep as is, no need to amp up. Nice plant ideas.
W. Wongo (original location #12)
A complex one. If the character chooses to fight, I'd give the su-monsters "regenerate 27 per turn", meaning that a single character needs to kill one, or it's fully fresh for the next.
I'd make each cursed character get attacked by a su-monster each, and to have the portcullis drop regardless.
I'd have each character killed (in animal form) by a Su-Monster stay dead when the Polymorph wears off.
X. X Marks The Spot (original location #14)
The Tomb entrance, that is.
Y. Bathhouse (Comp)
Solving the "pool of considerable depth" grants you Ubtao's Favor. I really love the variety of mazes conjured up by Sean McGovern.
Z. Red Wizards' Camp
Finally somebody telling the DM where this lot can be found!
Four Red Wizards (detailed below) a couple of
Veterans and perhaps a dozen
Guards or
Thugs, some injured.
Of course
they stay together - a single Wizard is trivially easy for a level 9 party. Instead, I'm envisioning them using their bodyguards and magical alarms and Thazma's divinations to ensure they don't get surprised easily.
If they become aware of an approaching party, they have two henchmen dress up as Red Wizards (bald heads, tattoos, red robes) and placed in the middle of the courtyard in the hopes the party waste their ambush on them.
You really should aim to kill at least one party member if the party assaults the RWs head on. I'm envisioning a very quick but very lethal combat, as is appropriate when you mess with several competent wizards. I haven't managed to kill a PC after they reached level 5, but hopefully this write-up gives me a decent shot
Of course if they manage to take them by surprise (despite magic) it's okay they defeat them without losing a single hit points - this is also what fighting wizards is all about.
Remember the possibility they want to parlay with Zagmira (right!). If they let one of them escape, don't hesitate to bring in Valindra and lots of tough undead.
Here are stats incorporating my version of d20 Circle Magic:
Zagmira is an
Abjurer (Volo 209) AC 15 (mage armor) hp 74+30 DC 16 but replace Arcane Ward with
• gains MR (advantage on saves) vs incoming Abjuration spells
• foes save with disadvantage on RW's Abjuration spells
• tattoo (circle magic)
• can cast a spell as a bonus action (4/rest) and then also cast Blade Ward
Zagmira's Red Cloak (req attn): 19 Intelligence (if lower), 30 temporary hit points (replenished by taking a long rest)
Zagmira's Spellbook: choose one Abjuration spell from your spell list – you count as having this spell known and prepared; 3 Potions of Supreme Healing (50 hp)
Tactics: targets most dangerous foe at a time; isn't afraid of warriors (she counts on Blade Ward to keep her alive for four rounds)
Attack spells w/o Concentration:
Dyrax is an
Evoker (Volo 214) AC 17 (mage armor) hp 78 DC 15 but replace Sculpt Spell with Red Wizard traits
• gains MR (advantage on saves) vs incoming Evocation spells
• foes save with disadvantage on RW's Evocation spells
• may choose to replace damage type with Fire for Evocation spells
• tattoo (circle magic)
Dyrax' Red Cloak (req attn): +1 AC, fire resistance; 3 Potions of Superior Healing (25 hp)
Tactics: all-out attacks
Yamoch is an
Evoker (Volo 214) AC 15 (mage armor) hp 54 DC 14 but replace Sculpt Spell with Red Wizard traits
• gains MR (advantage on saves) vs incoming Evocation spells
• foes save with disadvantage on RW's Evocation spells
• may choose to replace damage type with Fire for Evocation spells
• tattoo (circle magic)
Red Cloak of Dancing Flames: you gain Control Flames and Dancing Light cantrips. Furthermore, you can spend your action to gain Fire Stride (1/day). During one minute (concentration), you can spend ten feet of movement (once per round) to move from one fire (camp-fire or bigger) you're adjacent to, to another fire you can see within 500 feet, appearing adjacent to it.
Staff of Fire (req attn): fire resistance, cast Burning Hands, Fireball, Wall of Fire; 3 Potions of Greater Healing (15 hp)
Tactics: brings up defensive wall of fire if surprised; enables Fire Stride to split/surround foes
Thazma is a
Diviner (Volo 213) Init +6 AC 16 (mage armor) 67 hp DC 15 with Portent, and
• tattoo (circle magic)
Thazma's Red Cloak: You become proficient in making Initiative checks. You may cast a Divination spell as a reaction once per day.
Goggles of Night: +60 ft darkvision; 18 Potions of Healing (6 hp)
Tactics:
Links all four with Telepathic Bond; Handles the mercenaries; Provides information for the group: Arcane Eye, Comprehend Languages, Detect Thoughts, See Invisibility...