Asourn, God of Magic

Indestructible, Flying, Menace, Protection from instants
Asourn, God of Magic cannot be exiled.
When Asourn, God of Magic enters the
battlefield create 3 6/6 Magician creature tokens
with "When Magician enters the battlefield,
destroy target creature"
and 5 4/4 Young Magician creature tokens
with Reach