Sapling of Colfenor

The attack trigger inverts the usual card-advantage math: most reveal-and-draw effects reward you for big bodies, but here the creature you flip wants high toughness and low power, because you gain life off the toughness and bleed life off the power. That single line quietly defines the deckbuilder's job. Stock your library with fat, defensive creatures and the engine pays you in life and cards every swing; load up on aggressive beaters and each attack costs you a chunk of life for the privilege of drawing them. It is a deckbuilding constraint disguised as a combat trigger, and it rewards a Treefolk-and-walls shell whose creatures are naturally toughness-heavy rather than punishing it. The 2/5 body is the tell: this is a creature built to attack into open boards and survive blocks, not to win races, and indestructible means the engine keeps running through sweepers and combat removal that would normally shut a five-mana value attacker down. The flavor is precise too, the regrowth of Colfenor as a sapling casting his own funeral spell, but the design is the durable part: a recurring card-advantage motor that asks you to invert how you evaluate every creature in your stack, paired with a body sturdy enough to keep attacking until the question stops being whether it survives and starts being whether you survive your own draws.