Cas lets go of Ren's hand
Cas: ...
He's full of tension. He's trying very hard to control himself for Ren, but if Baku does anything to Ren he might snap
Cas looks at Ren, confused
Cas: What...?
Cas: W-what!?
Cas: Ren what is it!?
He seems kinda panicked, he doesn't want Ren to get hurt