Throne of Eldraine

A mono-color ritual bolted to a mono-color card engine, and the color you choose on entry is the leash on everything that follows. Four mana of one color off a five-mana artifact is a genuine surplus: it can chain into a second heavy spell the moment it resolves, or accelerate whatever single-color finisher sits highest in the deck. But that mana casts only monocolored spells of the chosen color, so a splash goes unfixed, gold cards stay stranded, and the artifacts and colorless payoffs a five-mana rock usually enables see none of it. The draw ability tightens the collar further: it shares the same tap symbol as the ritual, so in ordinary sequencing the two are mutually exclusive, and its must be paid with mana of the chosen color, which in practice means mana from your other sources rather than the same tap that produced the ritual. The result is a mana engine built for the one deckbuilding pattern most rocks quietly punish: the aggressively mono-colored build, where every card is already a legal target and the color restriction costs nothing. This is a ramp-and-refuel package for decks that have committed hard to one color, the least likely to want fixing and the most in need of raw volume. The trade is legibility for reach: narrow enough that off-color decks should skip it, generous enough that the decks it fits treat it as a repeatable ritual with a card-draw sideline attached.