Rules Question

(This is for definitive edition)
Nightmist has a card that says to summon an item or relic from any deck or trash. Does it go into her play area, or the area that corresponds to the card?

Whenever a card is played, it goes into its associated deck’s play area, regardless of who played it, unless something explicitly tells you to play it in another play area (such as Captain Cosmic’s Constructs, the Fey-Court’s Bonds, and Kismet’s Unlucky cards). This is also relevant for the Shinobi Assassins from the Temple of Zhu Long.