Zeri, Spark of Zaun

Mercurial Spelldancer can't be blocked.
Whenever you cast a noncreature spell, put an oil counter on Mercurial Spelldancer.
Whenever Mercurial Spelldancer deals combat
damage to a player, you may remove two oil
counters from it. If you do, when you cast your
next instant or sorcery spell this turn, copy that
spell. You may choose new targets for the copy.