Nagi, the Chosen One

When Nagi, the Chosen One enters the
battlefield, you may exile a legendary Demon
you control.
When Nagi leaves the battlefield, you may search
your library for a card named Susano, put it into
your hand, then shuffle your library.
Evoke {1}{w}(You may cast this spell for its evoke
cost. If you do, it's sacrificed when it enters
the battlefield.)