Artifact Creature — Assembly-Worker
Whenever you cast a historic spell, you may pay 1. If you do, create a token that's a copy of Mishra's Self-Replicator. (Artifacts, legendaries, and Sagas are historic.)
Since all artifacts are historic, this might have a home as a more resilient but slower precursor golem replacement in shops. The copies can also produce tokens, so if you play this followed by another artifact right away it is resilient to 1 STP since you'd still be able to make a token that can then continue copying. After 2-3 spells after this you'll have a crazy number of extra tokens. It's basically a big one sided genesis chamber that triggers off of all artifacts and makes more genesis chambers. It might be a bit too slow, but seems like a powerful engine for the long game in a grindy match.