I have to say seeing a monoblack midrange drain life deck in the recent 5-0 MTGO Standard lists was a bit of a surprise for me. This list from ALEHOP is very creative and I quite like it. We are all used to the adventure decks, winona, sultai ultimatum, monored… maybe a dimir control here and there, but seeing a deck with 4 Gray Merchants posting a 5-0 is certainly unusual.
I assume the idea here is to try to find a Gray Merchant, either naturally or by using Fiend Artisan and then sacrifice it to one of the many sacrifice outlets (Fiend Artisan, Ayara, Woe Strider) and then start bringing it back using Nightmare Shepherd and Nullpriest of Oblivion.
The deck works like a normal midrange deck that can curve out with some of the early drops like Serrated Scorpion and Priest, using Ayara to drain the opponent and set up for some pretty wild life gain swings with Gray Merchant and Shepherd later.
Even Shambling Ghast looks reasonable here as it can be sacrificed to Ayara, give you a treasure token and let you play Gray Merchant on turn 4. This deck looks very unassuming at first but I think I might give it a try in my next video and see how it plays out!