Alex Mercer

A very edgy dude and Shadow The Hedgehog's #1 fan.

Prototypal Devastator
Waking up in a facility with several gunshots and no memory except his name, Alex Mercer was being hunted by the Blackwatch soldiers, and discovers he can "consume" persons to expand his biomass, take their appearance on a genetic level and gain their memories. He then finds his sister, Dana Mercer, who helps him search for a girl called Elizabeth Greene who could help him regain his memories, she he finds she's captive in a Gentek facility so Mercer goes to free her, but she gives a cryptic message and escapes from Mercer.

Mercer is attacked by Captain Robert Cross, who injects a parasite in him which nullifies his powers, however Dana finds a doctor related to the experiments that removes the parasite, and recovers his powers, afterwards his sister is kidnapped by Elizabeth Green's minions as she has fused with the prime hive and now commands the infected, but Mercer uses the parasite in her, which causes her tu turn into the "Supreme Hunter" who is then defeated by Mercer, saving his sister.

He afterwards has a flashback where he remembers that he worked on the "Blacklight" bio-weapon project, but the government began researching and eventually cornered him when he tried to escape with a vial of the virus, which he released before being shot, explaining how everything began. Now the army planned to nuke the city, but Mercer infiltrated the U.S.S. Ronald Reagan with help from Cpt. Cross to do it, but once inside it was revealed Cross was actually the Supreme Hunter who had survived and consumed him. After being decapitated by Mercer, he proceded to rig the nuke to blast in the ocean along with him.

His remains washed up on the shore, and regaining biomass from nearby animals, he once again returned to his image stolen from Mercer, as he merely was a thing that absorbed his body upon death and not the real Mercer anymore.

As he felt the virus twisting his mind more and more, he became alienated by humanity and upon being betrayed by a girl he fell in love with, he returned to New York City, now renamed York City Zero, and left lose the virus again, hoping to consume all of humanity with it and cleanse it of sins and war. He infected James Heller to make him as Mercer expecting to create a subordinate but Heller betrayed him and finally absorbed him, ending what little remained of Mercer finally.

Season 3
Before returning to New York however, the Dimensional Merge drove him to the TFR wrestling federation to make it into his subordinates to conquer the world, but was stopped by a legendary hero.