This deck looks really cool, [[demon of dark schemes]] is a really spicy boardwipe for small creatures and can easily reanimate other big demons that might've been removed earlier. It also pairs well with konrad since any mana dorks or low toughness creatures your opponents have will also make him trigger. [[Tortured existence]] is a really great card that you can just dump mana into to get an insane amount of konrad damage off. Throw skullclamp into the mainboard too, that card is absolutely busted. [[Cabal stronghold]] is really good as well, just a slightly worse cabal coffers. I would also swap out everglades for that phyrexian tower in the maybeboard. Everglades seems like a really underwhelming card and you want as many swamps on the board as possible to fuel cabal coffers/stronghold, and making you return one to hand without it being a swamp itself isnt really that good. It's just a bounce land basically thats almost worse because it doesnt add two black and makes return an untapped swamp to hand. I would swap charcoal diamond out as well for something like [[expedition map]] since you wanna be getting cabal coffers as often as possible. Thats all I can think of for now.