To get the most out of him, you'll want to build a deck that can get Zombies out onto the battlefield while also having ways to reanimate them from your graveyard
Do Lands Count Towards Devotion
If everyone is stuck only drawing one card per turn, only playing one spell per turn, only attacking or blocking with one creature per turn, and so on, we should theoretically have a chance to be able to keep up with better decks
The rest of the deck was based around dumping cards in the graveyard for the Cauldron to exile and bring back the key pieces to your hand as required
But what really kicks it over the top is that middle part of his text box: Whenever an opponent casts a spell, if no mana was spent to cast it, counter that spell. You dont have to worry about an opponent casting a Force of Will while tapped out, or a free Fierce Guardianship or Deadly Rollick