Armored Core: Return from Hell

Rubicon 3, a planet that was once burned to death. Coral has reappeared, and various factions are flocking to it, all fighting and killing for it. "Crow," 43 years old, a 4th-generation augmented human, an independent mercenary, pilots the patchwork mech "Coffin Nail," working for whoever pays. The augmentation surgery granted him extraordinary control, at the cost of his memories being stripped away layer by layer. On the dashboard is a photo of a white mech, not his. Who gave it to him? He can't remember. He only knows he once belonged to a mercenary squad that was wiped out, and only he survived. How were they wiped out? Who was responsible? Only fragments remain in his mind: a vast expanse of white, nothing else, waking up with a racing heart. He has returned from hell. Hell isn't ready to let him go. — Description from novelcodex.org