An excessively prideful individual against one with absolutely zero self esteem. Quite the matchup, but that's some sound logic for the jellyfish - mostly water with a good bit of blood mixed in, and as long as he doesn't burn through the jelly's reserves, he won't need to use more blood!
He's probably a bit lighthearted at this point, though.. A large cost is still just that, even if it lingers longer.
Well, thanks for the chapter, but try to avoid forgetting to sleep!