Hearthpwn

First of all, this is a cheap malygos deck. There is no gadgetzan, prep, darkiron skulter, emperor or bloodmage thalnos. Which means you have vanish instead of board clear. You should wait malygos, at least 1 shadowcaster, one conceal and 2 sinister strike to finish your opponent clearly. When you have all of them, first play malygos then conceal. End the turn. Next turn, play shadowstalker on malygos and gain a 1-1 malygos. Then you will have +10 spell damage on board. Finish him with 2 sinister strike which cause 26 damage. Good Luck! (I will add a gameplay video after 15 upvotes.)