Black Clover: Season 1, Episode 104

1 - 104: Lightning of Rage vs. Friends

Magna had been training with Vanessa to become more powerful and during their travels they ended up in a town that was being destroyed by none other than Luck from the Black Bulls who had reincarnated as an elf. Magna and Vanessa do everything they can to try to stop Luck but Luck had turned into someone else and attacks them both. And because Vanessa's magic protects all the members of the Black Bulls it kept protecting Luck even though he was someone else inside.