Fused with an ancient artifact.
Kyoka Suigetsu attempted a one man coup that ultimately failed.
He was meant to be executed, but this ultimately failed due to the ancient artifact.
His wings were torn.
His body was sealed.
A sentence of 2.000 years.

But 1.000 years have passed.
Some took pity of him and let him walk with a sealed body.
But can he be trusted?

And when did you realize he was right behind you...?