What was this dudes' curse i already forgot

The curse is that the royal bloodline is bound to the Maiden of Heaven’s spirit because the original emperor forced her soul to stay tied to his family line. Because of this, she’s reincarnated over and over again to be used for her power. The princes, like Muon, inherit this curse. They’re marked with a scar as a reminder and suffer bloodlust that drives them mad if they don’t kill to satisfy it. It’s a cycle of corruption that can only be broken when the reincarnated Maiden of Heaven truly loves and is finally loved for who she is.

Thanks mate