Breezed through the first 7 bosses with Darius, only to end up against him as my 8th boss (which shouldn't be possible btw), only to get destroyed. Dunno what they were thinking with this Shallow Grave card, just because the AI makes poor play doesn't mean they should get uncounterable shit like this.
I've beaten him 2/2 times, once with the Cannoneer and once with the Huntmaster. I think the trick is to leave the Cult Masters alive while clearing the rest of the board, which does fatigue him. It's crazy though that he actually has 4 Shallow Graves in his deck. I see how it can be really difficult. When I was using Cannoneer I had to rely on holding back the treasure that heals your hero to full and draws 5 cards. When using the Huntmaster I just had to maintain board dominance.
My frustration was the third boss for me was one who steals one attack minions... I was like no problem, I won't summon any. She used a 1 mana card every single turn I played a minion that stole my minions and changed their attack to one. I think I died in 5 turns as I couldn't keep a single minion for 4 turns straight with her stealing them. and sadly, her spell wouldn't show up when I used Tess's hero power.
Alright, I just faced this piece of sh*t, and I'm very salty.
I was playing with Darius and had double life and my 10+ mana minions cost 5, i had 3 rag, 2 varian, 1 kel'thu'zad and others awesome legendaries, the first time he cast Shallow Graves I maneged to kill them all with King Mosh, them THE NEXT FUCKING TURN HE CAST IT AGAIN, I KILL THE BOARD WITH Deathwing, AND THEM HE CAST AGAAAIN AND THEN I JUST CONCEDE, I BEATED EVERY BOSS SO EASILY AND THEN THIS MOTHERFUCKING NECROMANCER FUCKED MY RUN, OMFG I'AM SALTY AF.
I battled him on fight 8 with Tess and it was super easy. I had frenzied trapper, cult of the wolf, double health, and the cartographer. Built my deck for health regen, and spells. Built my deck to survive till the long game where I would outvalue him. Didn’t have a card cost more than 5. Bounced my cartographer back probably 10-15 times. I abused him when he used shallow graves (3-4) times and a cult leader emerged. I used ricochet, beastiery, and about 4 of the 9/9 divine shield taunt. With gang ups I probably had 10 of the 9/9 divine shield in my deck when I won.