(!) Spoiler Alert (!) -- [Any Details Provided are Subject to Change] (Part 1)

I also must add that the Mercy/Maw and Mercy/Infernal King are the only combos in the game that will give a high level player any sort of chance of gaining traction on the leaderboard. That being said, that is the current meta. They are the only combos that will net you wins or hopefully a skip.