Why it sold: clean value, easy four-of, beloved character, fits many shells
Mastering the graveyard can yield some incredibly potent effects, so long as you play your cards right
If a player can activate Ashiok's -10 ability, they'll get to play with not only an opponent's entire graveyard but also all the cards in their hand, stealing away any potential plans they may have had to put a stop to the onslaught of exiled cards
As long as that's the case, Dragon's Rage Channeler becomes a 3/3 with flying that has to attack each turn
Right around turn 5, or even earlier if you are playing cheap cards, the game can devolve into drawing one card, and playing the one card you just drew
Facilier, Fortune Teller has a pretty mean ability