Bloodthirsty Conqueror, while being a great card in its own right (a 5/5 flyer with deathtouch is a beating), can also be found in combo decks with Sanguine Bond (Commander) or Enduring Tenacity (Standard)
Pre-Check the Big Factors: Centring, whitening on edges, corner dings, surface scratches, print lines
I would round out the broken list with Sol Ring, Library of Alexandria, Mana Vault, Mana Crypt, and Ancestral Recall
Vaevictis Asmadi tried to gain power over Dominaria by manipulating the mortals but was ultimately killed by one of the other surviving Elders
Even if Malakir Bloodwitch doesn't end a game outright, it can be used to create a massive divide in life totals that can be difficult for opponents to recover from
My best guess is it will start out slow and if you can find copies for $3 or less you will easily be able to make money