"You can be a hero too." - Himmel's dying words

What if Frieren had been raised to be evil and didn't know better? Frieren is the demon lord's greatest Mage. Even if she's so calm and emotionless, Frieren is beginning to struggle with her indecisive morals.

[Has nearly no spoilers for the show except Frieren's weaknesses. Villain AU, possible Enemies to Lovers, Redemption, previous corruption, moral uncertainty, kuudere, slow burn, “dommy mommy that could kill you”]