@Gorlom:
Don't think this manga is bloody enough for that power to be honest.
Uh, most of Zoro's fights except for Ohm and Hatchi consisted of him getting the holy living jesus cut out of him. Not bloody? Are you kidding? It's no Berserk, but it's plenty bloody.
Anyway, I would think the blood power would focus more on the effects of coagulating around the opponent, or bringing the blood to a boil and causing them to fry. Fun stuff, there.
Plus, great moments like this:
"It's Akainu! Shoot him and we'll get a huge bounty for sure!"
"Yarrr! I'll become a pirate legend!" Shoots Akainu with a shotgun
Akainu's head explodes in a mass of blood
"Holy crap! You blew his head clean off!*
Akainu: reforms his head Gotcha.