Uh...so...this is the first time Casimir involved in an au. Yep, ghost buster au with Malik aka Father Roth 😂😂 Cas as a nerd physic professor who can see ghost but get traumatise because he almost got killed as he tried to help them to cross over to the other side when he was a kid.
He invent his glasses to unseen the ghost. Something happens lately, the ghost sighting become relentless and he had to take the matters in his own hands, science style lol.

As he went to the site, he meet an obnoxious priest with unconventional way to handle this paranormal activities and he says that not all are ghost but there's demon in disguise.

However, they end up forming a duo as ghost buster 😂😂😂 Cas invent  the equipment for ghost trapping and weapon while Father Roth send them to where they are belong. 😂😂😂

Bonus:

P.s- this is a very fun au lol