Guiltythree
Cassie was able to hear and see Sin of Solace through Sunny’s senses but she didn’t have his protective memory against Sinny. So she got the memories and was corrupted when she met Sunny in the nightmare. Would explain why the corruption is undetectable and why she knows and has been acting strangely.
Guys wouldn’t she have know about her soul getting contaminated with the seed of corruption since day one of entering the nightmare? If I’m not mistaken, when she was celebrating her birthday with her parents, she said that she already knew how she would died, so potentially she’s going to died in this nightmare by the hand of one of the core members.
Cassies ability allows her to see the Future, but not JUST the future. she can see with other people's senses, see people's statuses, etc. it would make sense if she gained the ability to affect the senses of others, which would include sunnys ability to see her soul. it would be an interesting offensive use of a seer ability. perhaps connected to an unlocked lineage or something of the sort