Dark Sector (Xbox 360)

Dark Sector is an action game, in which the player assumes the role of Hayden Tenno, an elite black-ops agent, sent into Lasria, a small USSR country, tasked with the objective of destroying a virus that turns people into mutants and eliminating it's creator, Mezner.

Upon finding Mezner, Hayden is infected with the virus himself, mutating his right arm, which in turn gives him certain abilities, like turning invisible, creating shields and most importantly the ability to use the glaive, a special knife-like weapon that Hayden can use both in melee and ranged combat.

Next to the powers the infection grants him, Hayden can also use firearms, like shotguns or pistols, which can be taken from enemies or bought from the Black Market, and can also be modified.

Multiplayer has two different modes: Infection, where one players assumes the role of a fully mutated Hayden and the others hunt him down as ordinary soldiers and Epidemic, where two teams, each with their own Hayden, try to kill the other's mutant.

https://www.youtube.com/watch?v=fnsjVO3Y6Rw