Only way Sherazin, Corpse Flower would be good is if it started out dead so you had a 29 card deck and got a free 5/3 during your edwin, questing or miracle turns. As it is, its trash. Flame Imp trades into it which is terrible for a 4 drop, especially one that is a legendary..
but i foresee it will be very suitable or even staple for miracle rogue. since u will play it before ur miracle turn. Despite Conceal rotating out, its still doable for Rogue to have two to three miracle turn in one game. Even if u trigger it once, its 4 mana with two 5/3 which gives insane value already. It can be a sticky minion which encourages you plan ahead.
"What is the most OP card in hearthstone?"