This is in my "A" tier of gauntlet decks, meaning I get to the final boss nearly every time, and I can beat the boss most of the time. There are only a few decks that are sturdy enough to do that.
This deck is a madness/sacrifice base with Rolant to clutch wins with. Use of Wasteland is powerful, especially if you have some sacrifice cards and then create a bunch of Betray the Causes, one might even immediately pop up and become useful with warp. Of course use Ashara whenever you can by combining a madness/betray with a play. Oskar is a new xpac addition and he is outstanding.
A vast majority of the time I use my first wasteland to create 4 imprisons and those often win the game.
I am not sure the fascination with 75 card decks, I've found you can draw into a loss pretty easily. This deck has a lot of options as it gets cooking with reliance on cull/devour/plunder to massage out what you need. Try it out, may feel like a big deck, but it plays pretty smoothly and you can farm Gauntlet gold.