Being playable in any deck but only desirable in decks playing enough creatures to reliably crew it means that an aggressive player will generally end up with the Copter in their deck, and the power, evasion, and card selection that the card offers tends to give any aggressive deck a real shot in the arm
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This wont necessarily come up in a lot of Cubes or in a lot of Naya decks, but its something to keep in mind if you have a sacrifice theme and/or Threaten effects in your Cube
The Xanathar Guild is made up of some of Waterdeep's most disreputable folk, as well as monsters forced into subservience or drawn to the beholder by the promise of treasure, food, or power
Infernal Phantom is an interesting use of eerie, giving a temporary +2/+0 buff
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