Maloch finally gets to go and regenerates 20 hit points. He is still most likely around 150 hit points at this point and given he's a demon lord decides screw this fight, I can't win, I'm fleeing. If he's fighting on the material plane and decides to fight to the "death", he already has his concentration spell up, so he's rather limited. We'll assume he teleports next to the barbarian or ranger and breathes his breath on them. Most likely, he does this to the barbarian unless the ranger has spent her bardic inspiration dice somehow. The barbarian likely fails the save unless one of his allies give him inspiration (which they will, because duh). Still, for arguments sake, we'll assume he fails.