@Yili you shd take mysteric at her word n ask her for her bg cards except yuta, winwin, and doyoung, or as you wrote in her profile page zelo n all her zico.
Either way dont confuse her with the krystal unless its not for irene card. Shes active but like i said b4 you just hv to gently hit her over the head to get her attention.
Tldr: tag mysteric when shes active until she responds again(dont confuse the issue with irene card since she agreed to her bg cards to be traded for Luna already.)
I found i had to gently prod her a few times on the trade she already agreed to but she finally did it. Same here for Luna.
I hope im not interfering too much, if so ill leave off next time-just tat i think of mysteric as a fellow SM/Snsd/fx family stan so i feel kindly towards her.