Responses
The cat's eyes are purple now. Like suhyeon's eyes. So I think you're right. Suhyeon is in the cat.
[Spoil?]
Actually his soul was in the cat while he was still unconsicous, but he doesn't remember it all, but it was flashbacking little by little
IDK IF THIS IS A SPOILER BUT MY THEORY but I think that the boy somehow switched bodies with the cat, so he could spend some time with his lover