Rin and the rest of his class are assigned a mission. To guard and help Sam and Dean Winchester from Abaddon and anything that appears a threat. Will Rin be able to hide the fact that he's the son of Satan from the brothers or will Abaddon find out first and come after him. Sorry, crappy summary.
Shortly after being dragged from Hell by the angel Castiel, Dean finds two boys were not as fictional as he thought. Now the world rules are blending and there's no telling what the consequences may be, especially when it's Satan's kids they're dealing with.
I was bored so I started typing and this is what I got. Don't own Supernatural or Blue Exorcist. Basically Rin runs away in fear of losing control and Yukio gets help from the Winchesters to find him. What will happen when the Winchesters find out about Rin and Yukio being brothers? Will Rin return back to normal? Should I continue?