Devastation is a DLC bonus campaign in Resident Evil: Desolation. It lends you the option to play as one of two new characters: Chet Allison (B.S.A.A. Alpha Team operative) and Kyle Calahan (TerraSave security officer).

Much like the character select screen for the main campaign, the B.S.A.A. and TerraSave icons appear in the background of their respective characters.

Chet/Kyle's Story (DLC) Edit

Chet Allison and Kyle Calahan search the city streets of the infected Rhysport. They bypass hordes of infectees-turned zombies, horrific apparitions surrounded by massive clouds of viral hallucinogenic smoke, civilians screaming in mass panic while others are attacked and B.S.A.A. tanks and soldiers everywhere trying to stand guard and fight off hordes of zombies.

After briefly sticking together, Chet and Kyle go their separate ways, the former trying to attend infected civilians back at the hospital and the latter attempting to rescue the president's wife from the downtown university. Along the way, the B.S.A.A. guards get sucked into pools of black liquid, causing them to encounter horrific mutant jellyfish underwater. Fighting his way back to the surface, they eventually encounter a hive filled with Hellings in the middle of the city as civilians are mutating into terrifying B.O.W.s known as Eradicators after being parasitically controlled by the embryonic parasite B.O.W.s which were implanted inside the missile bombs by Varada.

Fighting through the Eradicators, Chet makes his way inside the laboratory. He ventures through the medical center, attempting to vaccinate as many infected civilians as possible. However, as he tries to get the antidote, he learns through fellow operative, Oliver Martin that the facility has been compromised, believing Umbrella to have sent a plant within the facility. Venturing through the facility, he again encounters Oliver in the hallway. However, he starts regurgitating as he's been infected with a dose of the C-Virus and T-Phobos while simultaneously being injected with a Helling parasite.

Chet defeats Mutant Oliver and continues throughout the many corridors, eventually finding fellow B.S.A.A. operative, Jessica, believing her to be the plant. However, mutant skin peels off of her where he shoots her after being attacked and thrown to the ground by her, revealing it to be a C-Virus clone. After battling and defeating the Jessica doppleganger, she starts metamorphosing, revealing her true identity hidden under the C-Virus clone. Identifying herself as Allie, she warns that her sister is being held prisoner at Rhysport University, to which Chet reveals that they've already sent someone to rescue her.

As this is happening, Calahan travels throughout the western part of downtown Rhysport, encountering Manta escaping from the sewer and attacking civilians as he tries to rescue the president's wife, Maria from Rhysport University. Along the way, he eventually encounters and battles a large crustacean B.O.W. Making his way through the zombie-infested campus, he ventures through the University, completing horrific puzzles and exploration in search of the president's wife. Encountering zombies, Phantasm, Creepers and Incubo, he eventually finds Maria being held hostage inside the school medical center. He rescues and leaves with her, protecting her throughout the endangered streets of Rhysport as he goes to meet up with Chet back at the treatment facility.

After safely escorting her back into B.S.A.A. custody-along with her sister-Chet calls the acting president and gets the OK to call in an air strike. The B.S.A.A. guards quickly evacuate the city before its devastation in order to prevent the infection from reaching New York City. Before long, they quickly hop onboard a B.S.A.A. chopper and watch the explosion take down all of downtown Rhysport.