Demonlord Belzenlok
The recursion clause does something most card-draw payoffs refuse to: it removes your control over how much you draw. Dig until you hit a nonland, take it, and if that card costs four or more, dig again. A deck built around expensive bombs feeds the loop and pays for it in life, one point per card, with no upper bound and no off-switch. That is the tension the design is built on. The Elder Demon body, 6/6 with both evasion keywords, makes the card a threat that closes games on its own; the entry trigger is the gamble bolted onto it. The math is deliberately self-correcting in the wrong direction: stack your deck with high-value haymakers to maximize the windmill, and you maximize the self-damage, since every chained hit is another expensive card and another life lost. Run a flatter curve and the trigger fizzles to a single card off the top. There is no comfortable middle where the engine runs hot and the life total stays safe. Belzenlok belongs to black's long tradition of life-as-resource demons, the cards that hand you cards or mana and let your own greed set the price; this one just hands the dial to your library instead of to you, which is a meaner and more honest version of the same bargain.
