Planet f*king Maloras

< In Acadmey>

Got it, thank you for providing that additional context. Here's an updated version with Luna being Derek's sister:

Ever since his traumatic encounter with his cursed sister Luna, Derek had been plagued by visions from the fragmented memories he witnessed when expelled from her psyche. 

Luna had been imprisoned in a mysterious cage, corrupted by dark forces into wielding unnatural powers. When Derek tried to free her, Luna lashed out and Derek glimpsed horrific scenes of her village destroyed and people slaughtered.

More disturbingly, Derek noticed shadows seeping into his own aura, drawn by lingering traces of the corruption he absorbed from Luna's tortured past. If left unchecked, these shadows could overwhelm Derek's light magic from within.

As one of the few wielders of pure light left, Derek knew he had to maintain balance, for the sake of both himself and his sister.