Responses
Nope, the blessing's condition for stopping is "burning thing dies". As long as Agni doesn't die the flames won't stop - even more now that Togata, the only person who new how to extract the part of Agni's brain where his blessing is located (so that he could regenerate the non burning part) is dead.
Yep, this is without doubt a tragedy.

Fire Punch... and his fire Punchess... oh my god. Someone remind me, do the flames go out if Doma dies? They probably don't as Agni is still on fire, but... hot damn... no pun intended.