I don’t think he is yandere for now I feel like Cain is just jealous which is completely normal when you like someone. Cain was at least way more calm and didn’t manipulate or hurt Jooin like Yahwi did when he saw Cain hugging Jooin, but who knows maybe he can be a yandere in the end T T
Cain seems nice only on the 1st glance....he's super sus & he give off yandere vibe which i really don't like