Karn, Argent Defender

A colorless two-mana ETB lock is a plausible sideboard tool, but its 1/3 body and symmetric text make broad maindeck use risky.

Could be wrong if Its result hinges on how many competitive Standard decks rely on creature or artifact entry triggers after release.

It closely matches Doorkeeper Thrull's 64-point job, gaining colorless casting and artifact coverage while trading flying for artifact and legend liabilities.

Could be wrong if Doorkeeper Thrull's adoption may be tied to white decks specifically; Pioneer ETB targets may not justify enough Karn slots.

It cleanly attacks the supplied Esper Blink field and other ETB plans, but a removable two-mana permanent is narrow and clashes with artifact-ETB decks.

Could be wrong if Modern may have enough resilient ETB engines to reward broad sideboard use, or too few for Karn to survive as a niche card.

Colorless ETB suppression has useful sideboard targets, but Legacy demands immediate, resilient interaction and Karn is a vulnerable symmetrical permanent.

Could be wrong if If artifact and creature ETB engines become a larger share of the field, its low casting restriction could make it more common.

A cheap colorless ETB lock is a solid stax inclusion against multiplayer value engines, but it also disables its controller's common creature and artifact value plan.

Could be wrong if Adoption depends on whether matching decks can avoid the substantial symmetry better than they value Karn's extra creature body.

A 1/3 for two is serviceable defense; the lock can punish the revealed token density, but will often be blank and can suppress its controller's triggers.

Could be wrong if Unknown archetypes and trigger density could make the static ability either meaningful main-deck disruption or nearly irrelevant.