Fury Sliver

Double strike is the multiplier that turns a Sliver board from arithmetic into geometry. Most of the tribe's anthem-style grants stack power, toughness, evasion, or a keyword that helps the body carrying it; this one rewrites combat math for the whole team at once, and it compounds with everything already in play. A pump effect that adds two power now adds four to the damage that lands. A Sliver granting trample no longer leaks a single point past a chump blocker but doubles the overflow. Lifelink doubles. First strike folds in for free. The cost is the body it rides on: a 3/3 for six is a poor rate in isolation, which is exactly the point, because the ability is priced against a board that already exists rather than the creature carrying it. Because the grant reads "All Sliver creatures," a lone copy is still a 3/3 with double strike, so it is never a blank; its danger simply scales with how many other Slivers you have committed. That gives it an honest tension: weakest when you are behind, most lethal when you least need the help, ending games the moment the swarm is assembled. The Sliver philosophy has always been that each member is a global grant the whole tribe shares, and few grants reshape a turn as completely as folding the entire team's combat damage in half again.