This means that if you are able to get some +1 counters on it or it is being buffed by other cards then X could be pretty high and almost guarantees you a card draw each time
However, Zhulodok isnt really the tool youll generally use to finish players
Each time you exile a creature, you pile counters onto one of your symbiotes, which quickly turns them into massive threats
Card prices are driven by supply and demand, but also by history, rarity, collectability, tournament relevance, and formats like Vintage, Old School, and Premodern
This also works as a win condition by first producing infinite mana, and then casting Venser with his two ETB triggers being an opponents permanent of choice + Venser