Since his release in 2019, he has been one of the most ubiquitous Black cards in the format, showing up in practically every deck that cares about sacrificing Creatures, reanimating Creatures, discarding Creatures or forcing opponents to discard Creatures, or Milling Creatures, which is about 90% of Black decks
She costs four in Boros, with double strike and a two power so that's four she's dealing base and could increase massively from there
I use sulfur. Matoc, lavamancer Illustrated by Glen Angus Standard Not Legal Alchemy Not Legal Pioneer Not Legal Historic Not Legal Modern Not Legal Brawl Not Legal Legacy Legal Comp
Extended Art Background for the graded card
The last couple of slots are more up for debate
In most cases, though, I only recommend buying directly from Walmart or Target themselves