Rosanna, Mistress of Blood

Eminence — At the start of your upkeep, if
Rosanna, Mistress of Blood is in the command
zone or on the battlefield, each opponent creates
a Blood token. Whenever a player sacrifices a
Blood token, if Rosanna, Mistress of Blood is in
the command zone or on the battlefield, you
create a Blood token and you become the
monarch.
The monarch can't lose the game.