Having a Supernatural + Mortal Instruments crossover would be amazing. Like can u imagine them finding traces of a werewolf (Luke) and when they find him, they’re about to kill him. Then, write as they’re about to drive him through with a knife or whatever, Clary either busts through the door and stops them or knocks Sam and Dean out with a fry pan. Either way, afterwards she convinces the two that Luke isn’t evil after a long time of trying and convincing. Then, they realize they both hunt demons and stuff and go on adventures together! The Shadow hunters ride behind or in front of the Impala on their motorcycles and everything is amazing.