Once reanimated by the Blacklight virus, every particle of Mercer's form, including his clothing and equipment, becomes comprised entirely of viral biomass. This substance can be manipulated at will. He can absorb the organic matter of other living creatures, converting it into more biomass. This process sustains and regenerates Mercer's health and is referred to as 'consuming'. In addition, Mercer can consume individuals, absorbing their knowledge, skills, and even their physical form, which he can call upon at will. He can manipulate his physical form to create weapons to attack his enemies, generate armor to defend himself, and take on the appearance of another person to disguise himself. During his battle against James Heller, he displayed the ability to consume multiple of his Evolved soldiers at the same time in order to power up his abilities.
Mercer's Blacklight infection has granted him the ability to both shapeshift and fashion his body into weapons. An example this would be his Blade resembling a giant sharp blade and his viral flesh possessing a yellow/reddish hue. His Whipfist has small razor-like blades across its spine-like form. Alex's evolved Hammerfists allow him to perform area attacks. He possesses consumption/assimilation abilities inherent in all infected creatures that allow him to take on the form and memories of any creature he consumes.
His incredible strength allows him to lift cars, trucks, the destroyed remains of tanks, APCs, and helicopters and throw them great distances. He is far stronger than any normal human or most basic Infected, able to kill a regular human with a single, glancing blow and manhandle the infectious residents of Manhattan. Mercer is capable of punching holes through almost anything if necessary, including a two foot steel door.
Mercer's speed is likewise enhanced. He can achieve running speeds surpassing vehicles.
He can perform amazing parkour feats such as flips and rolls and maneuvers over and around vehicles and debris with little trouble. His leg strength allows him to leap nearly ten stories into the air. Mercer can run up sheer vertical surfaces and cling to walls for an indefinite period of time. Mercer is also capable of gliding, by making his biomass lighter in the air and ejecting small amounts of mass for further propulsion.
Mercer's endurance far exceeds that of a human's by leaps and bounds. His body no longer possesses weak bones or vital organs, rendering him immune to otherwise debilitating injury. This biological change allows him to survive falls from any height completely unharmed. Bullets of any caliber will pass through his body, causing very little damage that heals instantly. He can withstand direct hits from rockets, hellfire missiles and tank shells, which cause only moderate damage. The superhumanly strong blows of the various type of Hunters and super soldiers cause the most damage of any type of attack. His superhuman stamina allows him to be physically active at all times without tire.
Mercer's body has vast powers of self-regeneration. So long as he is properly nourished, Mercer can restore his health and heal any wounds within moments. He can heal a small amount of his health even without consuming any creature. Examples include regenerating bullet wounds instantly after being shot, regenerating a massive hole in his face after being shot point-blank by General Randall, and reconstructing his entire physical form from non-descript piles of biomass and the biomass of a crow within minutes of being blown apart by a nuclear explosion. Mercer also seems to have a robust immune system. Though unable to counter a parasite which had been introduced into his body without outside help, he gained a growing immunity to bloodtox with repeat exposure.
Mercer's vision and hearing is enhanced, allowing him to see beyond the visible spectrum and hear across great distances even with physical insulation. He has thermal vision which allows him to locate heat signatures, and infected vision which can detect large concentrations of the virus and tap into the hive mind itself.
Encases Alex in a shell of armor which is resistant to damage and increases Alex's defence. While in this phase alex may sprint, building up his momentum to push aside obstacles such as tanks and other vehicles. He acquired this ability by absorbing a hunter he had injected.
Allows Alex to take on the memories and appearance of civilians, the military, and even the infected. To do so alex must first kill his target and absorb their structure to make use of their DNA. This may be used to play both the Infected and Military against each other, escape notice of your enemies, and learn useful information such as how to fly a helicopter. By disguising himself as a civilian the military will protect him from infected. by disguising himself as a sergeant in the military he can call down air-strikes, and tell his soldiers that someone else is the prototype.
Alex can alter his density and make himself very light enough to glide on wind. This helps him navigate through the city much easier.