The Cuniculus of Paradise

In the near future, the discovery of Akasha Particles promised humanity limitless energy — and delivered Gigantic Beasts that knocked humans off the top of the food chain. Survival now depends on massive humanoid weapons called Exos, piloted by Mercenaries who channel Akasha energy. The protagonist lost his ability to use Akasha Particles in an accident years ago. Disqualified from piloting an Exo, he considers himself broken and wanders in self-imposed exile. Then he meets a young girl who inherited her late mother's blueprints and built an Exo of her own — one scorned as an antique because it runs without Akasha Particles at all. A defective mercenary and an obsolete machine. An unlikely pair with more in common than anyone suspects.