Ikiral Outrider
Sink four mana on your own turn and a fragile 1/2 starts climbing toward something nothing wants to attack into: a 2/6 at the first investment, eventually a 3/10 that simply does not die to combat. Vigilance is what keeps it from being a pure brick, letting it hold the ground and still push damage back, but the defensive profile is the point. This is the patient end of the staged-mana-sink design that gave creatures something to do with leftover lands: rather than building a clock, it converts a flooded late game into an immovable anchor. The sorcery-speed gating is what permits a 10-toughness body to exist for incremental cost; each level can only go on during your own turn, so the wall arrives slowly and announces itself, never an ambush blocker that catches an attacker mid-combat. It cannot surprise anything. It can only outlast it. Among the creatures that ask you to feed them mana over many turns, this is the one that pays you back in toughness rather than threat, an early example of designers handing defensive decks a sink that scales with the game instead of a fixed line in the sand.
