Toph, the First Metalbender

The static ability quietly reclassifies your nontoken artifacts as lands, and that reclassification is the whole engine. Every mana rock, every Equipment, every artifact creature you cast now counts as a land in addition to its other types, which means the end-step earthbend can pick any of them and swell it into a body carrying two +1/+1 counters. The subtlety worth naming is the defensive one. Because an earthbended permanent returns to the battlefield tapped when it leaves via death or exile, most spot removal only stuns it for a turn. It does not return the same threat, though: the object that comes back is a fresh permanent stripped of its counters, so the recursion buys resilience rather than a stacking clock, and you have to earthbend it again to rebuild the body. What pays for all of this is the tempo. The trigger fires once per turn, so the board grows one animation at a time instead of exploding, and the reminder that these artifacts don't gain the ability to tap for mana keeps the reclassification from doubling as free ramp. Earthbend as a keyword treats lands as durable, self-recurring creatures; this design stretches that logic across an artifact shell rather than a lands-matter one, converting a widget you were already running (a Sol Ring, a Signet, a Bonesplitter) into a threat that shrugs off a Doom Blade.