Okay...
Heavenscent Breath (Recharge 5-6): The devadragon exhales a puff of energised steam at one creature within 5 feet of it. The target may roll a DC 11 Wisdom saving throw; failure means they go into a healing doze (convalescent narcosis) for one minute, during which time they are at Disadvantage on all Ability and Attack rolls, and can only move at half-speed, at the end of which they gain 5 (1d6+2) hit points. If they make the roll, they remain alert but only heal 3 (1d3+1) hit points. The breath weapon inflicts 2d6 radiant damage on all fiends and undead, with a successful DC 11 wisdom save halving the damage.
Let's see. I'm not that keen on having separate rolls for the healing and I thought we were only going to have it heal an individual once.
Would be clearer if the fiends & undead section was in its own paragraph, and I was thinking they should suffer disadvantage too. I'd prefer the damage to be typeless rather than radiant, since its other breath weapon does radiant damage.
Also prefer "vapour" or "mist" to "steam," which makes me think of scalding.
How about:
Heavenscent Breath (Recharge 5-6). The devadragon exhales a puff of energised mist at one creature within 5 feet of it.
A target that is not a fiend or undead immediately regains 1 hit point and enters a blissful delirium for 1d4 rounds. The target may attempt to avoid the delirium by rolling a DC 11 Wisdom saving throw. While delirious, the target regains 1 hit point at the end of each round but has disadvantage on all skill checks and attack rolls. On the target's turn they can choose to leave the blissful delirium as a free action but this also stops the healing. Once a target is healed by heavenscent breath they must take a long rest before they can regain hit points from another puff, but they can still suffer disadvantage from the blissful delirium. A puff of heavenscent breath heals a maximum of 3 (1d4 + 1) hit points to individuals who receive the full 1 to 4 rounds effect.
A target that is a fiend or undead takes [10 (3d6) ?] damage and enters a nightmare delirium for 1d4 rounds; if the target makes a DC 11 Wisdom saving throw they take half damage and avoid entering the delirium. While delirious, the target has disadvantage on all skill checks and attack rolls. The fiend or undead target can repeat the saving throw at the end of each of its turns. If they succeed, the nightmare delirium ends.
Hmm, that seems a bit wordy.
Anyhow, I'm not sure about the damage to fiends and undead. I was thinking it ought to be better than the
Radiant Breath, since that's its default damage breath weapon. But then, the radiant breath doesn't cause delirium to fiends so it kind of is better!
An
inflict wounds does 3d10 (16.5) while a 1st-level
cure wounds does 1d8+1 (5.5) suggesting the former does about three times the harm of the latter.
So I guesstimated 3d6 damage for the Heavenscent Breath against fiends. An Imp's sting does 3d6 poison plus 5.5 piercing plus it doesn't need a Recharge roll like its breath does, so that's not too excessive. The Imp sting is still a couple of points more damaging and it can use it at will.
A CR 2 White Dragon Wyrmling is supposedly two or four times nastier than our little angel, depending on whether we go for CR 1/2 or CR 1. It's got three times the HP and similar melee damage but its breath weapon is 22.5 damage plus its saves and AC are better but those are compensated for by its Deva & Imp grade special defences.
Hmm… it doesn't seem right to have the average damage output be identical to a Medium sized dragon wyrmling. Heck, a Gold Dragon wyrmling's melee is less than the Devadragon's at 9.5 average.
Maybe we should reduce the bite to a single point of radiant damage rather than 1d3 and
possibly the claws to 1d4?
I'd consider tweaking the Heavenscent damage to Fiends and Undead up to 3d8 or 4d6 damage vs Fiends or Undead so the Devadragon's Heavenbreath does similar damage to an Imp as the Imp's Sting does to a Devadragon. The latter's pretty much "save and die" as it's average damage on a save is higher than the platinum wyrmling's Hit Points.
It might be more prudent to give it
Damage Resistance poison so it has about a 50-50 chance of surviving an Imp sting if it saves.
In either case, it's looking like
Challenge 1 to me, with stats pretty close to an Imp. That's hardly surprising as we're aiming for a divine opponent for those wee devils.
