When you find the actor/actress who plays your favorite character in another tv-show/movie and she/he plays the bad guy.

Shit, Amanda Tapping who plays Naomi in Supernatural almost made Cas kill Dean!

Look how sad and heartbroken Cas looks after he had to kill a thousand clones of Dean!

But he still couldn't kill the real Dean!
Destiel
Destiel
Destiel
Destiel
Destiel
Destiel
Destiel