Throughout Marvel History, many villains and even heroes have worked under the name of Deathlok. The following are a few of them.

Origin

Luther Manning (Earth-7484)

The first published Deathlok - Luther Manning is from an alternate reality (Earth-7484). In this world, several corporations banded together to back Operation: Purge. The goal was to eliminate the Earth of all Super Heroes.

Manning was a high ranking officer in the world's US Army. When he was wounded in battle, he was transformed into the cyborg known as Deathlok. His creators had planned on controling Deathlok for their own means.

Deathlok was able to break free of their control. In escaping their control, he was transported to Earth-616, the mainstream Marvel Universe. In this world, Operation: Purge hadn't been implemented.

Deathlok joined forces with Captain America to stop the Operation before it could have its drastic effects.

Over the years, there have been other Deathloks created for dubious plans.

Recently, Deathlok had been under a coma, and was kept under S.H.I.E.L.D protection. Until the villain the Owl kidnapped him, and put him up for auction as a weapon. The criminal known as the Hood and his now organized group of villains bought him, and robbed a bank. Deathlok was trashed, and is currently under unknown conditions.

This version of Deathlok was also recruited by X-51 (Machine Man) of Earth-9997 into his group of Heralds, though i'm unsure of where this event falls in the timeline of events.

Michael Collins (Earth-616)

Michael Collins worked at Cybertek, a division of the Roxxon Corporation.

more to come..

John Kelly

John Kelly was created by the co-head of the C.I.A, for U.S. Army purposes. Harlan Ryker, the C.I.A co-head, studied the Deathlok body of Luthor Mannings for awhile before he created the John Kelly Deathlok.

After a few battles, John Kelly's mind and brain were transfered to a different Deathlok, named Siege. Siege continued battling

for the Army.

Jack Truman

Jack Truman was an agent of the international peace keeping force known as S.H.I.E.L.D. He willingly was transformed into a Cyborg by the Government to battle the Red Skull. The outcome of the battle is unknown.

Truman was eventually able to telepathically trade minds with a former S.H.I.E.L.D agent, Larry Young. Young was recruited for the 50 state Initiative program.

Other Deathloks have also been made, some more powerful then these, and some weaker. But one thing is true: The Deathloks have always been helpful, for better or for worst.

Powers
Deathlok possesses superhuman strenght that allows him to lift over a 150 tons, though he does not match the strenght of true powerhouses such as Hulk, Hercules or Thor, he is still very strong.  Deathlok's cyborg enhancements also give him superspeed which allows him to run up to 268 mph, Deathlok also has the power to manipulate and blast energy from his hands (similiar to Iron Man) Deathlok blasts energy waves or energy balls, Deathlok's gauntlets also allow him to shoot tiny nano-bots that hack into computer systems. Deathlok also has built in jet boots which give him the power of flight, Deathlok flies fast enough to break the sound barrier. Deathlok also has nano-second reflexes, superhuman stamina and agility and he is tireless due to being a cyborg. Deathlok has an impressove healing factor, his healing factor allows him to replace damaged organs but that is normally not needed for obvious reasons. Deathlok is invulnerable to many conventional weapons such as guns, knives, lasers etc. only things like missiles have the potential to harm him. Aside from physical powers, Deathlok can create force fields similiar to that of the Invisible Woman, he can blast electromagnetism as he is in the league of doing that with people such as Magneto and Doctor Doom. Deathlok also has telepathy which allows to communicate telepathically with other telepaths, he has telekinesis which he uses to move objects and people, Deathlok has a special ability to time travel, he opens a wormhole with his own powers which allow him to time travel. Deathlok has a sufisticated computer system similiar to that of the Iron Man Extremist suit, Deathlok's computer tells him about threats and such that it is in the league with Iron Man's computer, one of Deathlok's eyes have the ability to shoot lasers and it has X-ray vision and it also allows him to zoom in and scan the weaknesses, properties and strenghts of an object, being, person and weapon.

Weapons
Deathlok carries a powerful pistol that shoots energy blasts and once connected to Deathlok it shoots plasma energy and it has an interesting fact, it can only be used in the hands of Deathlok because Deathlok's hands produces unknown energy that is believed to power his weapon.

Alternate Realities

Earth-1610

Ultimate Deathlok (Luther Manning) makes a brief appearance in Ultimate Spider-Man #70.