Herbology Instructor // Malady Invoker

The front half is a lifegain speed bump: a body that pads your total by three and blocks patiently behind three toughness. The whole card turns on how it recycles that gained life. Because the transform cost is Phyrexian, the can be paid with two life instead of black mana, so a deck with no black sources can still flip it by spending some of the very life the enter-trigger just handed over. That is the elegant hinge: the resource that fuels the transformation is the resource the front face produced. When it becomes Malady Invoker, the -0/-X it inflicts scales off its own power. Note that this is toughness reduction, not power reduction: it does nothing to blunt an attacker's damage, it threatens to kill outright by dropping toughness to zero, and it wants a partner that can knock the target a point lower or ping it to finish the job. The sorcery-speed restriction is what keeps the whole engine honest. There is no mid-combat ambush of a blocker and no surprise on the stack; the shrink has to be arranged on your own turn, as proactive removal setup you commit to in advance. A modest card built around one clean loop of resources.