I'm about to DM a one shot(actually will probably be a two parter) and the 6 players have schemed up party fully composed of my 3 favorite 5e classes.
Paladin of the Ancients
Paladin of Devotion
Tempest Cleric
Light Cleric
Lore Bard
Valor Bard
A bunch of smart***es is what they are lol
How would you DM this party? Not sure what races they've selected, but knowing this group, they will all be heavily optimized. The original idea was to start them at level 5.
Mechanically...
Bear in mind Jeremy Crawford's clarification about combining game effects (e.g. Aura of Protection, Song of Rest, etc) in the DMG Errata here:
http://media.wizards.com/2016/downloads/DND/DMG-Errata.pdf TL;DR: apply the best one not both.
[section]
Combining Game Effects (p. 252). This is a new subsection at the end of the “Combat” section: Different game features can affect a target at the same time. But when two or more game features have the same name, only the effects of one of them—the most potent one—apply while the durations of the effects overlap. For example, if a target is ignited by a fire elemental’s Fire Form trait, the ongoing fire damage doesn’t increase if the burning target is subjected to that trait again. Game features include spells, class features, feats, racial traits, monster abilities, and magic items. See the related rule in the “Combining Magical Effects” section of chapter 10 in the Player’s Handbook.[/section]
Because they'll have so many healing options, don't hold back on monster tactics (i.e. go ahead and focus fire, hit downed PCs, and use dirty tactics). When you want to really threaten them, engineer situations that split the party (often, bards seem to do this on their own!). Also, the party is likely to cluster together to benefit from bard & paladin features, so monsters with area effect attacks should be particularly effective against that party. When running fey, fiends, or undead (which the paladins & clerics clearly want to face) keep in mind the party's ability to turn those things. And consider introducing imperiled NPCs who need succor/healing in the midst of combat, since the party excels at healing.
Story-wise...
I could see them all belonging to some kind of temple of a bardic/nature deity, perhaps one devoted to "the Song of Dawn" or something like that. I'm envisioning a church that emerged from a nature-based faith, something like the old Druidic orders of our world which merged priesthood, belief in spirits, ruling, protection of secret lore, and tracking astronomical/weather phenomenon. Maybe the Druids have mysteriously vanished from the world, and the PCs are trying to restore them or find out what happened? Or there is only one Druid at a time, who serves as the head of the temple OR fell from grace and is now the PCs' nemesis? Or the Druids are kept in stasis sleep in the innermost sanctum of the temple, and the PCs quest for a way to awaken them before disaster strikes?
This is also the kind of party that is begging for you to introduce moral dilemmas into the game...
- For example, bards are often more individualism-minded whereas clerics/paladins are more community-minded, so you can play on that when designing story beats.
- Another example: the devotion paladin is all about justice/virtue/order in support of "the greater good", following a code of honesty, courage, compassion, honor, and duty...whereas the ancients paladin is all about protecting/championing beauty, following a code of mercy/love/delight. So star-cross'd lovers breaking social mores at the expense of their parents would evoke sympathy from one paladin, but not the other. Similarly a question of whether punishment suits the crime could have the paladins with strong difference of opinion.
- And another example: the tempest cleric is probably all about courage/violence/swift justice/inspiring fear (think Batman-of-faith with lightning bolts)...whereas the light cleric is probably all about renewal/vigilance/beauty/truth. So a question of whether or not to make a preemptive strike on NPCs who are likely harboring villains but may not all be evil themselves, but the preemptive strike would make all the difference, yet there's an option to perform reconnaissance instead? That could drive a strong difference of opinion in the clerics. I imagine they could have different perspectives on representing "the truth" as well, with the tempest cleric willing to bend the definition to intimidate foes who he's quick to smite, whereas the light cleric might be more inclined to give the foe a second chance or clarify a misconception.