Lycanthropy

Whenever a player casts an instant or sorcery
spell, if you control another non-Werewolf
creature, create a 2/1 red and green Werewolf
creature token with "Champion a non-Werewolf
creature". (When the token enters the battlefield, sacrifice it unless you exile a non-Werewolf creature
you control. When the token leaves the battlefield,
that card returns to the battlefield.)
When Lycanthropy leaves the battlefield,
sacrifice all Werewolves.