Big priest and Raza priest are great choices. Raza priest stomps them a lot if they are slow unless they are running dirty rat. You can just stall and OTK them. Psychic scream will ruin their gul'dan or nzoth.
Jade shaman with Spirit Echo on key jade cards Before turn 8-9 and hexing/devolving his demons. Then go into Thrall Deathseer with new Brann-Elem. And watch them fatigueing themself. Don't forget to put some Heal.
The only problem is Aggro Matchups… Might be superfast loose against that.
Best counter is priest, Warlock just criest when they see a priest honestly, Big Priest can close the game faster but if you get a slow start it can be difficult to close the games and then raza priest is just the safe bet, unless both raza and anduin are on your bottom 3 cards then it's almost an auto-win. After than then really really fast decks can beat if they decide to run at least 1 Spellbreaker (I really feel like 2 are needed) but they also need a strong start, I'm running 2x Spellbreaker on my Tempo rogue and when my opponent goes for lackey I just silence it and that hits their gameplan really really hard.