Red Cliffs Armada

A 5/4 for five whose offensive relevance is decided by the defending player belongs to an older school of restriction, where a creature's drawback was a hard conditional read off the opponent's lands rather than paid with a sacrifice cost or a finality counter. The body is genuinely large for the cost: a 5/4 outclasses most things it would meet in combat. But the attack clause hands the on/off switch across the table. Your fleet only sails if the opponent controls an Island, and against anyone who doesn't, the Armada is reduced to a wall that happens to have five power, fine on defense and inert on offense. The asymmetry is the whole pitch: you pay for a top-end body and accept that its offensive relevance is contingent on the opponent controlling an Island. It reads as flavor-first design, a naval armada that only matters when there's water to cross, with the rules text enforcing the fiction literally. The condition is checked at the declaration of attackers, and it cares about control, not availability: a tapped Island still satisfies it, so an opponent who spends their blue mana doesn't strand the fleet. The threat goes live the moment they put an Island on the battlefield and stays live until it leaves, which makes Island removal or land destruction the only real way to switch the Armada back off once it's been turned on.