Saika no Majo wa Jiyuu ni Kurashitai

Riesz, a peerless archmage, lost her life as a human sacrifice to seal a magical disaster known as the "Magic Abyss." A hundred years later, she manages to return to life, only to find that the Magic Abyss's influence has transformed her back into a young girl. From El, a kind-hearted adventurer she saves, Riesz learns that due to the Church's schemes 100 years ago, she has been falsely branded as the arch-criminal "Witch of Calamity." Though outraged by this revelation, Riesz decides to enjoy her second chance at life. A refreshing fantasy where the strongest mage reigns supreme! (Source: Shogakukan, translated)