Rule 438.7

Tokens that have been Created through a Replace action can be instructed to be “Swapped back.” This may also appear as “replace [the token] with the [Game Object] it replaced.”

• 438.7.a Swapping Back is an extension of the Replace action.
• 438.7.b To Swap Back, the token stops existing and the original card is returned to the space that the token just occupied…
• 438.7.c If there is nothing in Banishment to swap back to then this object can never swap back.

Official Core Rules