Dragonlord Ojutai

The defensive conditional that makes the rest of the design work: hexproof while untapped means this dragon cannot be answered at sorcery speed before it has done anything, and it cannot be touched on your own turn until it commits to the attack. That commitment is the seam. Because the body has no vigilance, swinging taps it down and strips the hexproof, opening a real window for instant-speed removal during your combat, after declaration but before damage. The opponent who holds up a kill spell and waits for the tap gets exactly one clean shot per attack; the controller who reads that and simply declines to attack denies it entirely. Each connection that does land is a dig three deep, putting one card into your hand and burying the rest, so the dragon is its own clock and its own card-advantage engine without asking for a second spell. That self-sufficiency is the point: most evasive threats need a deck built to protect them, while this one shields itself everywhere except the combat step it chooses to enter. The lineage runs back through the Elder Dragon tradition to the original cycle, but the modern execution is what carries it: a 5/4 flier that punishes reactive removal by refusing to be reactive about itself, leaving the opponent to attack into hexproof, snipe the brief untapped-to-tapped window, or accept that a card may slip away on every swing.