How Irenicus's Vile Duplication Breaks The Legend Rule
The TL;DR: The Verdict
Yes, it really works that way. If you use Irenicus's Vile Duplication to copy a legendary creature, the resulting token is completely non-legendary. Crucially, if you then copy that token using a spell or a Populate effect, the new copies are also non-legendary (and they keep flying).
The Copy of a Copy Rule
Irenicus's Vile Duplication
Magic's rules engine is notoriously literal. When you cast Irenicus's Vile Duplication for {3}{U}, it creates a token with a set of modified characteristics. The token isn't legendary, and it has flying.
Many players assume these are temporary buffs or status effects layered on top. This is incorrect. Under Rule 707.2, these exceptions become part of the token's copiable values. The modified traits supersede the original printing. Any subsequent clone effect that looks at this token sees a basic, non-legendary flying creature.
This means cards like Rhys the Redeemed or Second Harvest can suddenly flood your board with legends. You can mass-produce Sheoldred, the Apocalypse without sacrificing a single copy to the legend rule.
Rhys the Redeemed Second Harvest Sheoldred,%20the%20Apocalypse
Breaking the Legend Rule
Elesh Norn, Grand Cenobite
Once the legend rule is turned off, Commander games break wide open. Legendary creatures are balanced around the restriction that you can only control one at a time. Stripping away that drawback turns powerful singular threats into absurd combo engines.
Imagine copying Elesh Norn, Grand Cenobite. The first duplication is a massive swing. If you start populating that non-legendary token, your opponents' boards evaporate while your creatures become colossal. Everything scales exponentially.
Miirym, Sentinel Wyrm
The same logic applies to triggered abilities. A board full of Miirym, Sentinel Wyrm copies will trigger for each other whenever a Dragon enters. The maths gets out of hand quickly.
Best Ways to Exploit the Loop
Token Multipliers
Adrix and Nev, Twincasters Doubling Season
Once you have the initial non-legendary token, you need ways to duplicate it. Adrix and Nev, Twincasters or Doubling Season will double your initial investment. However, you still need an active way to generate the next copy.
Populate Mechanics
Rootborn Defenses Song of the Worldsoul
Cards that explicitly say "Populate" are your best friends here. Rootborn Defenses protects your board while netting you another bomb. Song of the Worldsoul ensures every spell you cast adds another copy of your best legendary creature to the fray.
Pure Clones
Phantasmal Image Clever Impersonator
Remember, traditional clones like Phantasmal Image or Clever Impersonator also work perfectly. If they enter as a copy of the non-legendary token, they are also non-legendary.
Countering the Nonsense
Farewell Cyclonic Rift
If someone resolves the duplication and starts copying the token, spot removal targeting the token is critical. If you destroy the non-legendary source before they cast a populate spell, they are stuck. Removing the original legendary creature does nothing; you must snipe the token.
Board wipes like Farewell are the cleanest answer. Bounce effects like Cyclonic Rift also permanently erase the tokens. Do not let the token survive a full turn cycle, or the game is likely over.