Its day 2. It takes tine to find a good counter, and of course a new class will make a lot of players play that class.
DH obviosuly is strong, but who kones in a couple of weeks. I bet they will nerf a couple of the DH cards in the next few weeks, and then all will be good.
It already feels like warlock is a really good counter to it tbh.
Put down your little demon that pew pew a 10 random damage? Sound, I'll pop Zeraku down and then sac pact him. Cheers for the board and most likely more healing than you even damaged for. The amount of healing and lifesteal available for warlock helps stay out of their reach and with the ability to generate more spells you can dark skies, sac pact and plot twist out of all sorts.
It will most likely be less effective than it is now but for the time being it counters it quite nicely.
Also Priest is a good idea, as you might beat him thanks to copying some of their cards (they are almost all OP, so doesn't not matter too much with) and to the ton of healing.