Vampire Mode.

Take hero mode and do this.

One team is vampires the others is GR, like mutant mode, however Its all dark area's with little light, making use of weapon based flash lights.

Humans -
Like hero mode humans has access to all normal weapons and items, however the "hero" or squad leader takes the team into a catacombs like tomby area to hunt the vampires, also the "hero" is the only one that gets NVG's (night vision goggles) and they're aim to to kill vampires in the lair. However unlike mutant mode, you have to shoot vampire in the heart or chests area for them to stay dead, if not they respawn.

Vampires -
Similar to mutants, however they start off with 200 hp, and have ghost like cloaking abilities when they dont move. Have basic claw attack, or secondary attack that "grabs" the victim and you start to drain they're blood, adding their life total to the vampire's draining them but if you manage to drain a human dry, they turn into a vampire instead of dying, when a human is getting drained give them the ability to rapidly tap a button to get the vampire off. Also like mutant mode the more victims you drain the more abilities you get. Could be jumping higher, running faster, ect. The vampires goal is to kill off all the invading GR's that are there to hunt and kill them. Vampires Should also get "low light" vision, that is in essence like looking in black and white and humans could give off a "blood" aura for them to hunt.

I've havent seen a vampire mode yet in any of the "Modern Combat" games, yet there is Mummy modes (M.A.T.), Mutant modes (C.F.), Many Zombie Modes (M.A.T.,C.F.,War rock), Terminator Modes (M.A.T.), and werewolf modes (wolf team), why not add a vampire mode as a unique mode of game play.