Activate Slobad by tapping it and sacrificing Spine of Ish Sah, adding seven ({R} magic symbol) that can only be spent to cast artifact spells or to activate abilities of artifacts.
Spine of Ish Sah leaves the battlefield, returning itself from your graveyard to your hand.
Cast Spine of Ish Sah by paying ({7} magic symbol) .
Mirran Spy triggers, untapping Slobad.
Spine of Ish Sah enters the battlefield, destroying target permanent.
Repeat.
Results
Destroy any number of permanents on each of your turns.