So, I would like to bring up that the Draconomicon was one of my favorite 3.x era books, and I would be all for something like that making a comeback. Well, maybe not the Spellscales, they were kind of an “also appearing in this book” deal that I never saw anyone actually play, and now that dragonborn fill the niche of not-quite-half-dragon-people, it would probably be better to do something else with that space.
Way of the Ascendant Dragon
It's time to Rock the Dragon!
Draconic Disciple
Elemental punching makes this subclass already better than the 4 elements monk at being an Elemental monk!
Talking Draconic is ribbonish, but it's free and on theme.
Oh hey, using a reaction to re-roll a Intimidation/Persuasion check is fun and handy. It's rare to see a power that is useful both inside and outside of combat.
Important note!:
This power isn't powerful at all (monk fists already break damage resistance at level 6) but it does ooze with flavor. One small tweak I would consider is letting the elemental damage apply with any monk weapon.
Breath of the Dragon
You can replace one of your attacks with a “breath weapon” that deals 2x (or 3x) your MA die damage in an AoE. While not that powerful (seriously, that's like 5 average damage at level 3, 7 at 5 level 5, and 13.5 at level 11) it does have a resource pool outside of the monk's inherent Ki pool, which is an awesome mechanic. Heck, once it's proprietary pool runs dry, you can dip back into the normal Ki pool if you absolutely need it.
What I am saying is that the resource mechanic is splendid, even if the AoE is a bit on the weaker side.
Wings Unfurled
When you use Step of the Wind, you gain temporary wings that let you fly for the turn.
That part is cool.
Then it goes to muddle that up by using the same mechanic as the last power, making your super-step of wind cost KI and charges.
That just feels bad, it should automatically augment Step of the Wind, without the additional resource tracking. It's not like people are constantly spamming it to begin with, thanks to the Ki cost.
Aspect of the Wyrm
This one is cool, it gives AoE resistance and a reactive damage shield to your party, which is handy. Also you get one use for free per day, but can also dip into Ki should it be necessary.
Ascendant Aspect
As far as monk capstones go, this is one of the best ones. Passive free Blindsight, and your two “big-gun” powers get ramped up for free.
Thoughts:
So, this subclass is already gold star material as-is. And that elemental fist power should have been the starting point for the original 4-Elements monk (the other part of that particular rendition would also be the fluff elemental cantrips from the EEPC). Outside of Wings Unfurled being too clunky and costly in the resource management department, there isn't an ability that I have major issues with. My only worry is that people are going to look at this and freak out over damage vulnerabilities (again) despite virtually no monsters even having it. One tweak, make it obvious that the monk can use the elemental stuff on objects too! Lighting something on fire with your finger is a cool bar trick and it should be possible!
Drakewarden
The Beastmaster is back, in dragonish form.
Draconic Gift
You talk to dragons, and learn Thaumaturgy? Weird flex, but at least it's a fun spell.
Drake Companion
Following in the footsteps of the Artificer (and potentially the Tasha's Alternate Ranger), you gain a “fluff-your-own-stat-block” kind of pet. Only this time it's explicitly a summoned creature, which will make Fluffy's inevitable death even less permanent than before. Also, the Drake can infuse weapon attacks with extra damage as a reaction. Any weapon attack, so that crit-fishing paladin you pall around with will love them just as much as you do!
What is kind of bad: The summoned creature only lasts for a few hours each day. Sure you can use a spell slot to summon it again, but it just feels bad to not have the crux of your subclass available for the vast majority of the day.
Bond of Fang and Scale
Your pet Drake gets more mobility and damage. Also you get resistance to elemental damage while your drake is present.
Drake’s Breath
Essentially, a free (slightly weaker) Fireball once per day. Rangers don't normally get Fireball, in fact this subclass doesn't get ANY spell list (whooboy, that should change). But getting it two levels after you get level 3 spells, and weaker than normal, doesn't really feel that great even if it is free.
Perfected Bond
Your Drake gets Large, which means you can finally Ride it into Battle! Also it does some extra damage and you can use a reaction to give it (or yourself) resistance to damage. As far as Ranger Capstones go, that's one of the better ones. The problem being, once again, the limited duration of your subclass.
Thoughts.
So, in case I didn't make it clear by now: The Big Problem with this subclass is the duration of the summoned drake. Outside of Drake's Breath (which is sub-par to begin with) everything hinges on having your drake out, which can only be out for a few hours each day. And I mean everything, they don't even get a bonus spell list with things like Dragon's Breath on it to make up the difference. I get that making it a summon more or less solves the “My pet died” problem, but the summon duration creates a new and bigger problem in it's stead.