Yorick, Shepard of Souls

When Yorick, Shepard of Souls enters the battlefield create Maiden of the Mist, a legendary
3/8 creature token with "whenever a nontoken creature dies create create a 1/1 Ghoul creature
token"
Whenever a nontoken creature dies put a grave counter on
Yorick
Remove all grave counter from Yorick Create that
many ghouls then sacrifice all but four you gain 1
life for each ghoul sacrificed this way