The 4th level Polymorph spell enables an opponent to be turned into a beast.
There are a variety of largely harmless beasts into which an opponent can be transformed such as a sea horse (CR 0 with 1 hit point). Damage done to such a form spills over to the original shape according to the spell.
The challenge is that if one struck the sea horse - now you are back to fighting the opponent again.
Is there any advantage that Polymorph affords for subsequently dispatching an opponent? If so, how?
Presumably the party could chain all their attacks as reactions so they all hit at one time. Possibly the sea horse could be flown to a great height and dropped using levitation or fly. Is there some way to restrain a sea horse to ensure all hits are at advantage? Is there some way to ensure all hits are critical hits?
To narrow this question:
- We are looking at a standard party of four players of 7th level (i.e. they just achieved this spell.)
- No magic items - just raw abilities from leveling, in any combination, with or without spells.
- We are not looking for unusual environments. At its core - the question is looking for unique opportunities that polymorph opens up for dispatching opponents (as opposed to the alternative which would be one hits the "sea horse" and now you are back to fighting the opponent again.)