Metal Gear Solid 4 family tree

Raiden
First appearance: Metal Gear Solid 2 (PS2)
Nationality: Liberian
Affiliation: UNKNOWN
Looks like: Taylor Hanson
Voiced by: Quinton Flynn
Biography: Raiden was the unexpected fop hero of Metal Gear Solid 2, flooring fans expecting another Solid Snake game (unsurprising perhaps when you consider all the trailers for the game featured Solid prominently). Orphaned by the Liberian war, Raiden was adopted by Solidus Snake (another Big Boss clone), who manipulated him into becoming a powerful warrior.
What he’s doing in MGS4: Raiden’s had most of his body parts replaced with cybernetic prosthetics - he’s falling apart apparently. Not that you’d know it to see him fight - he can still make mincemeat out of a group of GEKKO Metal Gears with his high-frequency blade. He’s onboard to help Snake out - but does he have his own agenda?