If you somehow exile multiple creature cards with the same Assimilation Aegis (probably because its first ability was copied or something caused it to trigger more than once), you choose one of the exiled creature cards each time its second triggered ability resolves. You don't have to choose the same one each time.
When Assimilation Aegis's second ability resolves, the creature Assimilation Aegis is attached to copies exactly what was printed on the original creature card and nothing else. It doesn't copy any information about the object the card was before it was exiled.
When the creature Assimilation Aegis is attached to becomes a copy of an exiled creature card, it's neither entering nor leaving the battlefield. Any enters-the-battlefield or leaves-the-battlefield abilities won't trigger.
Last observed on Scryfall 2 months ago at $1.35. Over the trailing 90 days the price moved between $0.41 and $1.49 across 107 observations. Cross-checked across TCGplayer, eBay sold, Cardmarket EU, and Star City.
This printing is one of 2 catalogued treatments from OTJ — the lineup includes Extended Art alongside the standard finish. Across our catalog the Rarix library tracks every variant in the same family so collectors can compare price, scarcity and demand inside a single lineage.
Card #348 of *Outlaws of Thunder Junction*, the set that shipped alongside the April 2024 Outlaws of Thunder Junction release.
Card type: Artifact — Equipment, color identity blue/white, printed at mythic. Mythic rares historically land in roughly one out of every eight boosters at standard print densities. Mana cost: {1}{W}{U} (3 converted). Keyword abilities: Equip.
Legal across the major constructed formats — Modern, Legacy, Vintage, and Commander — plus Standard rotation play.
EDHrec ranks this card #9,751 in Commander, putting it in the niche-pick tier of the format's playable pool.
Illustrated by Matt Stewart. Rarix catalogs 988 other cards credited to this artist.
Magic: The Gathering · ™ & © Wizards of the Coast · Illus. Matt Stewart
Card data via Scryfall. Rarix is fan-made; not endorsed by the rights holders.
If Assimilation Aegis leaves the battlefield before its first ability resolves, the target creature won't be exiled at all.
Any non-copy effects that applied to the creature Assimilation Aegis is attached to before it becomes a copy of another card will continue to apply once it becomes a copy. The same is true of any counters that are on that creature.
If there are no creature cards exiled with Assimilation Aegis when its second ability resolves, the creature Assimilation Aegis is attached to won't become a copy of anything else. It will remain just as it was.
If you somehow exile a noncreature card with Assimilation Aegis's first ability (possibly because it was a copy of a creature while on the battlefield), you can't choose to have the creature Assimilation Aegis is attached to become a copy of that card when Assimilation Aegis's second ability resolves.
