Diffusion Sliver

Sliver tribal has always been about offense: stacking keywords until a board of 1/1s reads as a lethal puzzle the opponent has to solve. The defensive half was the gap, and this is the answer Wizards landed on. By taxing every opposing spell or ability that points at one of your Slivers, it turns the deck's biggest structural weakness (a board that folds when a key target gets picked off) into a wall of surcharges. The tax is the design lever that stops short of an outright Mana Leak on a stick: a determined opponent can still pay through it, but only by spending mana they would rather use on their own development, and they have to do it for every removal spell, every turn. Stack two of these and the tax doubles per pointed effect, which is where the card earns its place in a tribe that wins by accumulating redundant effects rather than leaning on any one of them. The catch lives in the wording: it protects Slivers that are targeted, so it does nothing against a board wipe that names no targets, and it cannot save itself from a sweeper either. It is a hedge against spot interaction, not a fog against everything, and that narrowness is exactly what lets it sit at two mana without warping the games it shows up in.