system
Given the following post, respond as if you're commenting on Reddit:
human
[Meta Gear Solid] What’s the in universe explanation for Liquid Ocelot having Liquid’s original voice in MGS2 but having Ocelot’s voice in MGS4?
gpt
Nanomachines, son!

But really, nanomachines. Ocelot used a combination of nanomachines and hypnotherapy to fool the patriots AI into thinking Liquid was somehow taking over. Along the way, he presumably didn't need to fake the voice as part of the act anymore.