I didn't make it targetable as it then in my opinion becomes OP. This random way is great as it means you may lose that Dragon or not, up to a spin of the wheel not by choice.
Dragons usually don't have that much problem with poison, as they can survive a bit even poisoned.
Basically, there are two ways of getting creatures poisoned:
- single creature poisoned (targetted by creature, devouring poisonous creature, etc.) - since there is only single creature poisoned, the Monk will heal the correct one,
- massive poisoning (plagues, poison shield, etc.) - here the Monk can provide massive healing
So, by making it target random creatures, but allowing it to clear unlimited poison, the Monk will be good in both situations.