Rebbec, Architect of Ascension

Protection normally keys off a color or a card type; this static ability keys off mana value, and the template that results is one of the strangest ever printed. Every artifact you control gains protection from each mana value that appears among your artifacts, which turns a deck's cost distribution into a defensive lattice. The wording is self-referential: the shield only covers the numbers you actually have on the board, so an artifact at a given cost cannot be damaged, blocked, targeted, or enchanted by anything sharing one of those numbers. The build tension runs opposite to intuition. Assembling artifacts across a spread of distinct costs (a zero-drop, a one-drop, a two-drop, and upward) widens the range of mana values you are protected from, so density at many different numbers is the goal; the values you fail to represent are the lanes left open, not the ones you stack. It rewards deliberate curve-sculpting over raw ramp, and it asks the pilot to read an artifact curve as a firewall rather than an engine. The self-referential clause has a quiet catch: as a Human Artificer, the commander is not herself an artifact, so her 3/4 body adds nothing to the grid she creates. She is a rules engine that must be fed from elsewhere, and the Partner tag lets a second legend join her. This is a puzzle-box more than a threat: an effect that treats every converted mana cost as a coordinate you either defend or leave undefended.