Rosheen, Roaring Prophet

Almost nobody has built a payoff mechanic around the letter X itself, and that is the genuinely strange thing here. Most ramp produces generic mana that pays for anything; this ramp is restricted to costs that contain , which means the mana only flows into a specific corner of the design space: the Fireball line, the Hydra line, the Comet Storm and Villainous Wealth line, spells whose entire identity is scaling with whatever you feed them. The enters-the-battlefield mill six is not graveyard fuel in the usual sense; it is a dig that only cares about pulling an X-cost card into hand, so the two halves reinforce a single deckbuilding thesis rather than offering unrelated value. That colorless-only, X-only mana is the constraint that keeps the tap ability from being a generic Nykthos, Shrine to Nyx: you cannot dump it into your curve, so the whole engine collapses if the spell base is not stuffed with variable-cost cards. What lifts this above a Timmy build-around is how brutally the mana math compounds: reveal three X-spells, add six colorless, and a single tap turns a modest board state into a lethal Fireball for the table. Commit to a narrow archetype most sets never quite support, and the output no fixed-cost ramp piece can match is what comes back.