Jolting Merfolk

The whole design hinges on spending a clock as a resource. Fading gives the creature exactly four upkeeps to live, and the tap ability draws down that same pool of fade counters: every creature it locks down is a turn shaved off its own life. That tension is the point. You can tap an attacker or blocker four times across the body's lifespan, or you can spend the counters early and accept the trade. It is an attrition piece dressed as a Merfolk, asking you to ration taps against the threat board rather than fire them freely. The friction also closes off the obvious abuse: there is no infinite tapping here, no engine, just a finite stack of disruption that ends with the creature sacrificing itself when the counters run out. The fade-counter pool doing double duty as both lifespan and resource pool is the elegant part: each activation is a literal expenditure of remaining time, so the cost is paid in turns rather than mana. Jolting Merfolk is one of the more honest expressions of what that countdown structure was for: a temporary effect that prices its own disruption against its own death. The body underneath is incidental; the value lives entirely in how you sequence those four taps before time runs out.