I want to discuss the newly spoiled card from Ravnica Allegiance...

Lavinia, Azorius Renegade UW
Legendary Creature - Human Soldier
Each opponent can't cast non creature spells with converted mana cost greater than the number of lands that player controls.
Whenever an opponent casts a spell, if no mana was spent to cast it, counter that spell.
2/2

List of cards it counters...
Force of Will
Chrome Mox/Lotus Petal/LED
Omniscience
Miracles
Belcher Decks
Past in Flames/Gifts Ungiven/Empty the Warrens
Cloudpost/Ancient Tomb/Eldrazi Temple/Metalworker/Spirit Guide/Dark Ritual/Seething Song if they’re not casting a creature with that mana

It’s a shame it doesn’t hit Show and Tell or Sneak Attack.

I think it might be decent as a sideboard card in Miracles for the mirror and combo matchups? Or is it too narrow to see play?