Metal Gear Solid 4 (Guns of the Patriots)
In 2014, Liquid Snake had apparently taken full control of Revolver Ocelot, creating the new entity: "Liquid Ocelot". In reality, Ocelot later replaced Liquid's arm with a cybernetic one and from there on he had merely pretended to be Liquid to trick the Patriots. Before his death, Ocelot referred to himself to Solid Snake as "Liquid's doppelgänger". Big Boss later explained to Snake that Ocelot was able to recreate Liquid's consciousness using nanomachines and hypnotherapy. Meanwhile, Liquid's corpse was put to further use; various body parts of his were used in the process of rebuilding Big Boss' damaged body.
One can wonder nevertheless if Liquid's spirit totally left ocelot after he took a cyborg arm. Indeed, like on Shadow Moses where Ocelot knows the 'FOXDIE' events when Liquid died, it seems unlikely Ocelot by himself could have known that much. Did something of Liquid remain in Ocelot? The mistery is whole...