Cavern Whisperer

Mutate turned mono-black's hand-attack effect into a repeatable trigger tied to a decision most disruption spells never ask for. A discard spell fires once and heads to the graveyard; here the same "each opponent discards a card" is stapled to a mutate trigger, so it pays out every time you stack another mutating creature onto the pile. That reframes the discard from a one-shot tempo hit into a cumulative engine: build a mutate stack, and each new body joining it strips another card. The menace on a 4/4 does real protective work, because a mutate pile is a single creature carrying every ability beneath it; keeping that pile evasive defends the whole investment rather than one card. The tension the design resolves is that mutate wants you to over-commit resources into a single target, and a removal spell punishes exactly that; pairing the archetype's central risk with recurring disruption gives the deck a reason to keep going wide-into-tall even when the board math says stop. What holds it in check is the mutate cost and the non-Human targeting clause: the discard only fires when you have a legal creature to build onto, so the engine is only as reliable as the bodies you can feed it.