Counterattack System appeared when I'm already At The Mahayana Realm - Chapter 734 - 733

The constant mission is getting redemption.

Shuttle though various worlds to become a variety of scum men, do a little whitewashing and become a good man in the eyes of everyone.

Redeem those who are miserable, and let them live a happy life.

- Description from Novelupdates

Fate, a gatekeeper who had been working for the castle, is beset by a few burdens.

One moment, he was playing Haikyuu: The Mobile Game; the next, Taichi found himself transported into the world of Haikyuu.Transmigrated as a member of Aoba Johsai, Taichi was presented with the opportunity to face the fabled main cast of Haikyuu.[The Genius Omni-System is activating...Please wait...]“Hinata Shoyo? Kageyama Tobio? Ushijima Wakatoshi? Bring it on! Let the Monster Generation line up—I’ll take on ten of you!”Follow Kaedehara Taichi's journey from a no-name in Volleyball to the 'Absolute Monster' of the Monster Generation.“Gear up Oikawa-san, for we are about to win it all!”

On the brink of destruction, I regained consciousness and found myself back in the past, 20 years ago. In order to have a peaceful retirement, I must prevent the impending doom.