Collector's Case

Stun counters usually arrive one at a time, stapled onto a removal spell or a fight effect as a consolation prize: they buy a turn cycle, not a lockdown. Two on entry changes the math. A creature holding two stun counters has to burn two would-be untap steps clearing them (each untap removes one instead) before it can attack or block again, and this puts both counters down on the way in for two mana, with no sacrifice and no combat requirement. The activated ability is the follow-up: an on-demand tapper that keeps a fresh threat horizontal for a turn whenever you have the mana, or that re-taps the same creature once its counters have run out. That combination builds a soft lock out of counters rather than out of the repeatable-tapper lineage that runs from Icy Manipulator forward, which froze a permanent but never forced it to dig out from a backlog the way stun counters do. The distinction matters for what it answers: a big attacker or a creature that relies on tapping to use its abilities stays neutralized across multiple turns from a permanent that costs almost nothing to deploy, and the counters persist even if the artifact later leaves the battlefield. Blue rarely gets to sit on a creature this cheaply without countering or bouncing it, and doing the work with a counter mechanic makes the effect durable in a way tapping alone never was.