As a test subject in the same Weapon X program that had previously given Wolverine his adamantium claws and skeleton, Wade Wilson received a healing factor that prevented his cancer from killing him.Marvel Source
Wade soon escaped the program and became a freelance mercenary using the name Deadpool, working for various criminal organizations. At times he has teamed up with heroes as well, but these attempts at "being a good guy" rarely stick for long.
Wade is mentally unstable, though whether this is a normal state or is caused by his constant state of hyper-regeneration is unknown. One side effect of his mental state is the belief that he is not a real person but actually a character in a comic book.
when aoe'ing trash, foot gougers and flesh wounds. for bosses, stink bomb, ALoD in, drop foot gougers, BSBO out and armor buster. repeat when/if needed til boss is dead. i know adding the dot from flesh wound is more dps, but i have both buttons set to my RMB and alternate with the F keys, so i usually don't bother with FW dot on bosses.
as for legendary, i know there's arguments for gungnir, appollo's bow and others, but i went with norn stones. yeah, i know, no one will know what the attributes will be like come january or whenever they update them. i just figured i do enough damage as is, and if the reworked attributes are horrible next month, i'll have enough odin marks for a different legendary.