My Janitor Dad is the Mecha God

Three years after failing to save his wife, legendary mech pilot Vic Thorne vanishes into a life of humiliation as a lowly janitor. When his estranged son, Leo, is nearly killed by a spoiled heir in a televised mech trial, Vic presses the neural key his wife left behind and awakens Type-Zero, humanity's lost war machine. As an extinction-level Abyssal invasion begins, Vic must reclaim his identity, save his son, and become the Mecha God once more.