Overwhelming Intellect

Counterspells that draw a card are an old idea (Forbid, Dismiss, and the like all let you cash a stopped spell for cardflow), but tying the haul to the countered spell's mana value is a different bargain entirely. Against a one-drop it does almost nothing worth six mana; against the big payoff threat the opponent built their whole turn around, it counters and refills your hand by four, five, six cards in a single beat. Narrowing the target to creature spells is the discipline that pays for that scaling: it cannot answer the planeswalker or the board wipe, so it lives or dies on the assumption that the scariest thing your opponent casts wears a power and toughness. The reward curve is deliberately backloaded. A cheap counterspell wants to be efficient early; this one waits for the late-game haymaker, the moment when an opponent commits their fattest threat and you turn their ambition into your card advantage. It is a tax on overcommitment dressed as a counterspell, and the higher the spell they cast, the worse the trade looks for them and the better it looks for you.