Containment Priest

Reanimation, flicker, and "put a creature onto the battlefield" effects share one structural blind spot: they sidestep the stack and place bodies into play without ever casting them. This is the white answer that closes that door, and it does so with a precision earlier hatebears could not match. The exile clause fires only on nontoken creatures that enter without being cast, so it leaves your own hardcast threats and your own token swarms untouched while wrecking an opponent's Reanimate, their Natural Order, their Show and Tell. Flash is the wrinkle that turns a static piece of hate into a reactive trap: holding it up lets you ambush a Sneak Attack activation or a reanimation spell, exiling the payoff before it can attack, and the 2/2 body still pressures the board if the game stays fair. Earlier answers to cheated-in creatures tended to fail one of two ways: they hit too broadly, catching your own engine along with the opponent's, or they sat passively where everyone could see them coming and play around them. Note the seam in the answer: anything that genuinely casts its creature, cascade and similar play-from-elsewhere effects, slips past, because casting is exactly what this card permits. Folding the answer into a flash body is what makes it dangerous: it asks nothing of your deck when you do not need it, and functions as a surprise blank against an entire category of strategy when you do.