Kaifuku Jutsushi no Yarinaoshi

Redo of Healer follows Keyaru, a healing Hero whose power can mend any injury no matter how severe, and should have made him a savior. Instead, that gift traps him in years of torture and abuse, until the heroic future he was promised collapses into a nightmare. While enduring that hell, Keyaru secretly uses his healing to absorb the memories and abilities of everyone he treats, slowly transforming himself into someone far more dangerous than the people who broke him. After reaching the edge of his potential, Keyaru realizes the life he lost cannot be restored. He unleashes a powerful healing spell that rewinds the entire world to the time before his suffering began, giving him a second chance armed with the pain of his past and the knowledge he gained in the future. With those advantages, he sets out to redo his life, navigate the world through his new power, and pursue a single purpose: revenge against those who wronged him. Every step of that second chance forces him to confront how far he is willing to go to claim it.