Leviathan Zero: Return of the Drowned Kin

Once a respected fleet commander, Rowan is branded the Drowned Traitor after a massacre wipes out his family and fleet. Elara rescues him and he goes into hiding, working quietly as a mechanic. When an attack leaves her near death, the giant mech Leviathan Zero stirs to life, pulling Rowan back into the war. He rises to expose the Vane Consortium's kaiju scheme, and the sister he thought was lost turns out to be alive, changed into a living power core.