1. Colossus (Piotr Rasputin): While he's primarily known for his ability to transform his body into organic steel, Colossus has been depicted as a cyborg in some storylines. This includes the "Age of Apocalypse" storyline, where Colossus has a mechanical arm after a battle.
2. Forge (Eugene Judd): Forge is a mutant with the ability to manipulate technology. He often creates advanced weaponry and cybernetic enhancements for himself and others. While he's not technically a cyborg, his reliance on technology to augment his abilities makes him a borderline case.
3. Mystique (Raven Darkholme): While Mystique is a shapeshifter and not a cyborg by typical definition, she has been depicted with cybernetic implants in some storylines. This includes a cyborg arm in the "Age of Apocalypse" storyline and a mechanical eye in the "Astonishing X-Men" series.
4. Cypher (Douglas Ramsey): Cypher is a mutant who can decipher any code, including those of technology. While he doesn't have cybernetic implants, he effectively controls technology around him with his mutant abilities. He's often depicted with a neural link to technology, making him a unique form of cyborg.
5. Cable (Nathan Summers): While Cable is a mutant with telekinetic and telepathic abilities, he was also born with a techno-organic virus, which gives him a connection to technology. This virus was later revealed to be a cybernetic implant, making Cable a cyborg.
6. Domino (Neena Thurman): Domino has a cybernetic eye and was a former assassin trained by the Weapon Plus program. While her cybernetic enhancement is minimal, she is often considered a cyborg.
It's worth noting that the definition of a cyborg can be fluid, and the X-Men universe is full of characters who blur the lines between human and machine.