Like most Magic: The Gathering cards, the value of Bleak Coven Vampires depends on a few consistent factors: its rarity, the printing and finish (regular or foil), its physical condition, and the set it was printed in (The List)
Greasefang is one of the only ones and I am taking full advantage of that here
Cards like Lithoform Engine, which double down on those juicy activated abilities, are a great place to start
Every time a creature attacks, it gets +1/+0 for that turn, and every time you play a land, you get another attack
As with all best of one games on MTG Arena, there is a hand smoother at work, which means you are more likely to get functional opening hands and play a relatively straightforward game of Magic
She doesnt have an immediate impact on the board like the usual control finishers do