Sword of Minerva (The Guild Wars)

Taiki Sato had long been the genius behind the Winged Hussars’ success. He spent years innovating, discovering new technologies, and generally making a nuisance of himself. But when he took his first trip to 2nd Level Hyperspace, everything changed. He created an innovative pinplant design, which he had Nemo, the Hussar’s Wrogul physician, install. A short time later, he executed a perfectly planned escape, disappearing from New Warsaw.
The new pinplants had awakened memories previously forgotten. A thought here, a scene there. Bit by bit, he began to realize he was missing a huge part of his life’s memories. Maybe most of it. So, with one of the clones of Rick Culper, a deceased marine Nemo had resurrected to experiment on, Sato snuck away to find out how far down the rabbit hole his memories would take him.
With Rick’s body installed in a new, incredibly powerful suit of armor known as an Æsir, the two return to Earth, where Sato was born. But he’s not the only one interested in his history; powerful entities from his past are very curious where he’s been.
The journey of rediscovery will take Sato back to the beginning, not just of himself, but of how he’d changed the course of humanity’s involvement in the Galactic Union. And—if he and Rick didn’t have enough to deal with—they have a stowaway.
In the end, he will find out who and what he was. The Sword of Minerva.