Ivorytusk Fortress

The wrinkle is the timing: this Elephant untaps your counter-bearing creatures during every other player's untap step, which means a creature that should stay tapped from blocking or tapping for an ability is back up before any opponent gets to act. Note the construction: this is a static ability rewriting the rules of the untap step, not a trigger that goes on the stack. It simply makes the untap happen, once per opponent's untap step, with no window to respond and nothing to counter. In a one-on-one game that buys you a single extra readiness window per round. At a multiplayer table the rules modification applies on each opponent's turn, compounding into something closer to perpetual vigilance: your team of counter-creatures sits untapped through the entire turn cycle, ready to block on the next opponent's turn, to feed activated abilities, or to stand back up before your own combat comes around again. The design hook is the gating clause, "with a +1/+1 counter on it." That restriction stops the effect from being a blanket untapper and ties it to a deckbuilding axis: anthems that pile on counters, proliferate, hardened-scales effects, or creatures that grow themselves. The 5/7 body is built to survive the board it presides over rather than to threaten, fitting a card whose payoff is positional rather than explosive. The more bodies you stack counters onto, the more the asymmetry hardens into a standing wall of available creatures.