Ladies and Mentlegen,
Looting… *ahem* Exploring the abandoned London is difficult enough with only Aura and Skyhammer backing you up, so a few Mercs have offered their services pro bono. These Free Rotation Mercs will be equippable by anyone, allowing you to try them out and get more flexibility out of your squad.
Enjoy them while you can, though. Different Mercs will rotate in and out periodically, and the only way you'll be able to play with the Mercs rotated out is by purchasing them, either with Credits or through the Steam Wallet.
Current Free Rotation
Fletcher
"You get what you pay for. I am the best. So I cost more. This is natural."
Fletcher is another of Dirty Bomb's mercs, but he's not a lightweight speedster like Proxy. His default shotgun, the aptly named Ahnuhld-12, has the best range out of all the shotguns, with with his average health and speed, he can hang out in the fray a bit longer than Proxy, popping in and out of cover as he fires.
Aside from Fletcher's Engineer Training, allowing him to interact with many objetives at 3x the rate of non-Engineers, Fletcher's main ability is his Sticky Bombs. These explosives deal strong AoE damage when they explode, and while a single sticky bomb can't kill someoen at full health, he can have three out at a time, and stick to any most any surface, be it walls, ceilings, objectives... or even other players. While he normally must manually detonate them with the Detonator, they will also explode when damaged, so be sure to take care of any enemy Sticky Bombs you see.
Redeye
"I spy... with my red eye... something beginning in... BANG!"
Redeye is a sharpshooter and scout, whose mere presence can completely alter the battlefield itself. With his default Grandeur SR, a battle rifle nestled snugly between the PDP-70's semi-automatic sniping and the Dreiss AR's flexiblity, he is master of the midrange, popping the heads of anyone that steps out of cover.
But his ability to control the battlefield is what makes him shine. Redeye can throw Smoke Grenades, covering the area in white smoke, blocking anyone without infrared sight from being able to see through it. He can also activate his IR Vision ability, seeing through the smoke and Spotting enemies for both his own rifle, and for his friends.
Sparks
"Call me Sparks. I heal. I kill. Is ironic paradox. Yadda yadda."
Sparks is a new breed of Medic, thanks to her signature weapon, the REVIVR Revive Gun! With her high speed and low health, she's ill suited for a firefight, but that's no problem, given that with the REVIVR she can do her reviving from half a map away, as well as hitting for some heavy damage. The weapon can only sustain a full charge for so long, however, and will overheat if leaned on too heavily.
Sparks uses a machine pistol and semi-automatic pistol, well suited for close-range work, for when the REVIVR is just not the best weapon. While she doesn't carry the standard-issue Defibrillators that Aura and Sawbonez favor, she carriers her own brand of combat healing, the small Health Packs, healing for a fraction of Sawbonez's packs, but bringing the user's health up immediately, even if they're in the middle of combat.