(11/10/2020) Untapping an attacking creature doesn't remove it from combat
It was only when alternate mana acceleration like Mana Vault got taken away that players finally noticed how good Metalworker was and started tuning their decks with Metalworker in mind
Its used to represent creatures whose blows are enhanced either by magic techniques or complex martial arts, rather than raw strength
You can create powerful chains with him, wherein you play an aura on Chishiro, thus creating a token, then play an aura on the token, creating another, and so on
The deck Ive seen does run Aetherflux Reservoir like most life-gain decks should, but more often than not it is winning with combat damage thanks to Treebeard, Gracious Host
Classic and thematic artifacts return, such as Steel Overseer (a must for Modern Affinity decks), Key to the City (great for evasion and fueling the graveyard), Meteor Golem , Solemn Simulacrum , Hedron Archive and, of course, the ubiquitous Sol Ring