Oltec Matterweaver

The clever move here is the second mode, which quietly turns a token-doubler into a token-multiplier. Copying an artifact token you already control means the value compounds: build up a few Gnomes with the first mode, then start copying a Treasure, a Blood, a Powerstone, or one of those Gnomes to snowball whatever token engine you have already assembled. Each creature spell, not each artifact spell, feeds the trigger, so the payoff scales with a go-wide creature deck rather than an artifact-matters shell, which is an unusual place to hang a copy effect. The 2/4 body is doing honest work too, absorbing early attacks while the engine warms up rather than folding to the first blocker. What keeps it from spiraling is the target clause on the copy mode: it can only duplicate an artifact token you already have, so it produces nothing on its own and needs the board state to have already started before the interesting half comes online. Cast it into an empty board and it just makes Gnomes. Cast it with a Treasure or two down and a follow-up curve of creatures, and it becomes a repeatable artifact-token photocopier that asks only that you keep deploying bodies.