I threw together metalcraft with "as long as . . . equipped" creatures, and not for the first time, but I wanted to make this something for speed and power together. Of course, using equipment as the sole source of artifacts helps both sides move toward their respective goals, but it is more than that. There are far cheaper options in some cases, and stronger ones in other cases. I wanted to go in the direction of blocking and punishing, so that is the secondary element here. The name derives from one of the four properties of metals. The (1)/17/15/6/1 curve is a seemingly insane 1.73, but costs to equip will make that seem more reasonable.