Containment Priest is a backbreaking answer to Show and Tell and Sneak Attack, since any Atraxa, Grand Unifier, Emrakul, the Aeons Torn, or Griselbrand put onto the battlefield without being cast is exiled instead of entering. Trinisphere raises the cost floor to three mana, which meaningfully slows their ability to deploy Show and Tell or Sneak Attack on turn one or two off Lotus Petal and cheap mana. Chalice of the Void at one is still solid against their Ponder/Brainstorm suite but Containment Priest and Trinisphere are the higher-impact additions against their actual game plan. Cut Chrome Mox and Sheltered by Ghosts, which are too slow or reactive against a deck trying to cheat a giant threat into play as early as possible.