My Childhood Friend Doesn’t Know I Was the Demon King.

Regression should have been a myth, a fairytale, for fools, but behold, the all and mighty Demon King, scourge of realms. After his eventual death, returned back to his past, back to his feeble human body, back to his childhood friend, Amelia, the same woman, who was to be the fabled hero, the Messiah, the liberator, the same woman who had pierced through his heart with her sword, gifting him a death full of regreat, full of remorse.