By being able to lock your opponent out of casting spells of any one colour when she entered the battlefield, Iona may as well have read "your opponent doesn't get to play Magic." Spark it: Read our beginner's guide to MTG Jumpstart In a Modern deck like Gifts Ungiven - where the eponymous card lets you put Iona into your graveyard only to reanimate her later - she can enter play on turn four, and close the game from there
Theres a lot of reasons for this, and some immediate effects that we need to be aware of, plus some trends we can get on now
It is a Psychic card illustrated by Sekio
When you play this character, you may return up to 2 character cards with cost 2 or less from your discard to your hand
Finally, Niv Mizzet deals additional direct damage, and Crackling Drake grows with each spell you cast
After the exchange, Tree of Perdition would be a 2/9 creature (its toughness became 7, which was then modified by Cultist's Staff) and the player's life total would be 15