Tangle Kelp

Blue's removal in this era worked by erasing a threat: bounce it, freeze it, or counter it outright. This Aura does something stranger, taxing a creature's offense by chaining its untap step to its willingness to attack. The design splits into two gears. The enters-the-battlefield tap is a one-shot tempo play that blanks an attacker for a turn, while the persistent clause turns the enchanted creature into a liability for any controller who wants to keep swinging: attack, and it stays tapped, leaving no blocker behind. The card never resolves that tension; it simply makes the choice cost something. That makes it less a piece of removal than a behavioral leash, a soft Pacifism that only bites when its controller commits to combat. The friction lives entirely in the conditional. A defender content to sit back shrugs the whole thing off, so the Aura's power scales inversely with how aggressive the creature already wanted to be: it punishes the beater and ignores the wall. The restriction checks whether the creature attacked rather than imposing a hard lock, which makes it a gentler ancestor of later tap-down prison effects that simply deny untapping outright. For a single blue mana, the structural logic is unusually clean, and it captures a moment when blue's answer to a problem creature was sometimes to make attacking expensive rather than to make the creature disappear.