Cryogenic Stasis

Cantrip plus clearing a blocker has some tempo value, but two mana for a temporary creature answer is a major cost in Modern.

Could be wrong if A spell-dense tempo shell may value the cheap cantrip and two-combat stun more than expected.

Legacy's cheap threats and interaction make a two-mana, nonpermanent answer unattractive even when it replaces itself.

Could be wrong if A creature-heavy metagame could create a narrow tempo-sideboard role.

It can force through attacks and deny a creature a combat while cycling, but it competes with cheaper interaction and permanent answers.

Could be wrong if Pauper blue tempo decks may find the card-neutral stun sequence more effective than its temporary text suggests.

Replacing itself helps, but temporarily disabling one creature is low multiplayer impact versus durable removal and broadly useful interaction.

Could be wrong if A commander or deck that specifically rewards tapping opposing creatures could make it a real niche inclusion.

At instant speed, it removes a blocker, suppresses the creature through its next untap, and replaces itself for only two mana.

Could be wrong if The unknown format speed, creature density, and available tap/untap effects materially affect how often its tempo matters.