Xolaani, Traitor of the Darkin

At the end of combat if you attacked with
Xolaani this turn you create a blood token.
Blood tokens have " pay{1}: Sacrifice this
artifact, draw a card."
After a blood token is created or sacrificed,
target creature gets -1/-1.
Sacrifice 6 blood tokens: Xolaani becomes
a 8/8 with flying.