Tazri, Beacon of Unity

Cost reduction with a hard ceiling is an unusual thing to build a payoff around, but that ceiling is the whole point. A full party caps the discount at four mana, no matter how many creatures you flood the board with, so the design can print a genuinely aggressive body knowing the arithmetic will never run away from it. Assemble the maximum spread and the five-cost 4/6 arrives for a single white mana; assemble anything less and you pay for what you skipped. The discount doubles as a construction test, because hitting the full reduction means you have already fielded the exact class distribution the activated ability wants to replenish. That ability is the engine underneath the discount, digging six deep for the party's four classes plus Ally, and its twobrid pips (each payable as a colored mana or two generic) let a disciplined mono-white shell run it without ever splashing the off-colors. Party rewards a tall, focused creature count and taxes off-type filler; this card answers both halves at once, giving you the reason to stay lean and the refuel to keep the hand stocked once you are. The 4/6 is the underrated part of the pitch: sturdy enough to survive the removal a one-mana threat begs for, cheap enough after a party to land while the board is still forming. It sits at the head of the party-tribal lineage as the card that makes the mechanic's math actually close.