Growing the Seed of Evil

She was reincarnated as the world's strongest swordsman and an unparalleled beauty with silver hair. But you're destined to be killed by the final boss sooner or later?! Astrea finds the final boss in danger and decides to raise him himself to rehabilitate him, who is still a child... … . “Let’s go with me from now on. Sigrian.” “… … This is the first time, someone said this.” Yes, it was good to raise the future final boss well into adulthood. the problem is… … It was that he was revealing his true nature (?) to the other side. “Every time you smile at that bastard, I get angry and go crazy.” Somehow, it seems that the seeds of evil have been nurtured incorrectly.