Okay, I'm sorry, but this is completely ridiculous. I may not have a whole lot of power in this rp, but a character who can just release massive clouds of disease at enemies sounds like a very bad idea. What, pray tell, would happen if your character spontaneously gained the ability to, say, utilize the Ebola Virus or HIV? You could autokill anything that moved. Not even Henry's superpowerful immune system could fight off Ebola, and if your character gained the power to use HIV he could wipe enemies' immune systems clean instantly. Even if you say "well he doesn't have those diseases at his disposal and gaining them would put him into a coma (which by the way makes no sense)", the diseases you listed him already having are still extremely powerful. Smallpox has killed more people than any other disease in the world, and the Bubonic plague still kills people today even when the patients are treated with class III and IV antibiotics.

EDIT: Okay, so this was a little harsh. I apologize for being a dick Harbinger (I'm kinda sleep-deprived right now so I'm being a little cranky). We don't mean to dogpile you or anything (though tbh it kinda looks like that) but a lot of people on this website submit some fairly OP characters for stuff like this (I've seen death manipulation, reality warping, and the ability to spawn the actual Satan. It's baaaaad) and after a while it starts to annoy you. Your's isn't as bad as a lot of the others, though.