my oc, killer snake without his assassin hood, bandana, and glasses on , which looks pretty cool, is also a royal assassin, and also protects both the mane 6 and the cmc's, and he can never die, plus he feeds off of both fear and insanity, thats why hes so powerful against all enemies
You may want to flesh your character out more. You've got a starting point, now explain it; Where does he come from? How did he come to be an assassin? How did he become immortal? What does he fear? Do other ponies like him, or are they scared of him? I believe that answering these questions will help create a more satisfactory character who has room to develop and grow.