Sekiryutei Vassal Hero

Summoned before the First Wave, Issei becomes the Sacred Gear Hero. But once he learns how incompetent the true Hero's of the story are when they arrive, he might just have to be the Hero that ends the Calamity of the Waves. He just hoped that he was strong enough for him to bring about the end of the Waves and be the Hero this world needs. Hero's get babes right...?