My Giantess Legion Makes Me God

In a world where Awakening Exams dictate destiny, men become Warriors and women transform into colossal Giantesses. Only through "Mental Synchronization" can they fight as one. In his past life, he was a nobody who witnessed the world’s strongest Giantess go berserk and annihilate Earth. Now reborn, he discovers that the future "World Destroyer" is actually his classmate! Armed with future knowledge and a unique "Infinite Link" ability, he must sync with her to uncover the truth behind the madness and rewrite the fate of humanity. Source: Webcomics