This is basically a control deck. The units are mostly to gain life, so you can be more greedy with removal, to trade away or to bait opponents removal. Having Mournful Deathcap for several turns is something a lot of opponents misjudge and ignore. If they want to focus them with removal though, you have other units to punish them.
The Black Market is in constant flux and can be adjusted how you like.
Be aware of the combo-potential between Deathcap, Dreamsnatcher and Lost Scroll.