The double-X is the seam this format pries open. TMT is a medium-speed legendary-payoff environment where six- and eight-mana turns are normal and the common removal suite (Grounded for Life, Stomped by the Foot, Bot Bashing Time) is largely sorcery-speed and creature-targeted. A flier that lands and immediately drops X bodies pays its full freight in a format that actually reaches the mana to cast it big, then turns that board into a flying clock your opponent has to break before the next attack step.
P1P1 for any white drafter, and through the first few picks you take it over nearly anything in your colors. The natural home is RW or WB goodstuff where the curve tops out at six and seven: there you cast it as a six-mana enter-for-two-tokens that swings as a three-wide flying threat the following turn. WB Sacrifice wants it less, because the tokens want to attack rather than feed Anchovy & Banana Pizza loops, and BG Food has no reason to splash double-white. The sharper fit is any white deck holding Equipment: a Bespoke Bō or Novel Nunchaku on one of the 2/2 Soldiers converts the attack-step flying grant into a real damage spike rather than a token gesture.
With Sneak across 59 cards, even the X=0 line (a 2/2 flier for two that enables a Sneak trigger) is a genuine mode, not a desperation cast. Working against it: Dimensional Exile and Grounded for Life both answer the body before any attack trigger fires, so the floor is the enter-the-battlefield tokens and the ceiling demands you protect through one removal spell. The Turtle mythics and Shredder, Unrelenting still outclass it as singular finishers; this is the rare that closes when you've drawn none of your own.

