It's the kind of crazy story he wouldn't have given a second thought to; identity switches, brainwashing, the miserable works. Mad scientists, straight out of the movies. He didn't need to take more than a step away to find it hilarious - monsters, built piece by piece; brainscanning, hypnotism, soul-crushing; children who weren't, one on his side (tap tap tap, just like a video game, IAWTC) and one who thought she was but tried to kill him anyway (a Queen born when the pawn hit the other end of the board, promoted in place of the captured one). He has no faith left in logic. It's disappeared. Even through his empty, unmemorable mind and past (although his his past seemed eventful if they were to be believed) he'd prided himself on his cool head, rational decisions, intelligent speculation.
Now he knows, though, that he'll have to prove them right or wrong. He's a woman tied to the ducking stool - if he can't demonstrate his powers, he'll drown in the dust of this place, dying away; and if he can save himself, it would only be by outing himself to the witchfinders. He has to try to save his own life, but he knows that, if he can, it will prove his own life meaningless.
He climbs. It's heavy going. He strips off his backpack, sheds the launcher, lets the missiles (guided in battle by skills leached from a mind that wasn't his, he'd never handled any FIM weaponry before coming to this place, never seen a Stinger, but in this new neon world even memories were processed, packaged, meat) roll to the sides, loses the heavy flak jacket with its pockets for weapons too heavy to carry with him any more. Wherever he was going, he wouldn't need them. The scarf he lets drift down to the floor, and he's left in the thin skintight underlayer, the layer his expansion chip cheerfully declares to be a lightweight imitation of a suit worn by a legend in some nonexistent universe. His hands lock into the metal joints, and he heaves himself up. His body screams.
He reaches the top and is amazed that the air isn't high-altitude thin. It feels like he's climbed the world. He slides into the black, featureless cockpit, and doesn't even wonder what he needs to do because it is the most natural, instinctive thing in the world - pleasure dizzies his mind for a while until he feels the hard electricity of the cables he's hooking into his skin and feels the nanochips tingling and fizzing with power and he's entered and finally his consciousness comes free with a scream of the most amazing pleasure he's experienced in his (short) life that he can remember, and he lets out a cry of release through massive steel jaws, a dinosaurian roar. Power surges through him as he stands on metal legs. In his right hand is the potential to destroy the world, and it feels so much better than he could have imagined. He's wounded, and he feels the sting in his face as he moves to tear through the wall which gives way like tissue paper, but he's so mighty now it barely matters. This is what he was made for. This was his body. The twitching, juddering, senseless thing inside his black, featureless mouth, eyes dull and dry and unblinking and dead, was a distraction - nothing more than a novel means of transport. His true body had never been that, been that soldier. His true body had always been the Metal Gear.
He scans the world with a range and depth and colour of senses he could not even begin to understand before, moves forward, listening to the squeal of his own joints, and wishes desperately there was some other way. The knowledge of what came next was a looming Damocles sword. He'd reached absolution, he'd reached complete bliss, Nirvana, ascended and become one of the Chaioth Ha Qadesh. It wasn't fair that he had to discard both power and bliss (two pair, six COST added, next turn) to continue living. But that was why he was different, more so than stupid things like the neuron-chips and flesh-wires he was made up of. His instinct to survive. That was what they wanted, why he existed at all - put that instinct in the most powerful machine ever conceived, and the world would have no defence. And he is willing to obey that instinct.
He moves his human body and seals him away in a capsule, a case, something. Even hidden from his visual sensors he is able to see his shape (radar), read his vital signs (MG Mk.2 processor), peer at the expansion chips in his hand (common knowledge to anyone who cared enough to look).
He senses a faint trickle of wind, and looks down to see the tanks, beaming up at him with long hungry cannons, and he fires. For a moment he is convinced he has died, but then he realises that he has broken the connection, and this is his limited human perception, streaming along in this fragile metal case, this fragile flesh case trembling in the movement, the fear, the withdrawal. It's all blackness, pain, vulnerability.