A Lone Wolf
Watching Elijah's retreating figure disappear into the darkness, Elian couldn't accept the fact that his deceitful brother visited the palace occasionally for Cas's sake alone. He knew this because Elijah's presence signaled trouble wherever he went, and if possible by the end of tomorrow night when they meet again, Elijah would be long gone for him to no longer worry about his intentions.
Getting Elijah out of the way is the only possible option he could come up with to reach the monster who ruined his life and that of Elijah's. If they hadn't been abducted all those miserable years ago and turned into the freaks they were today, maybe life would have been different for the both of them, just maybe, he wouldn't have to cut ties with his family and build an uncanny hatred for his own blood brother.