Steel Overseer turns a battlefield of artifact creatures into a growing army. Tapping it places a +1/+1 counter on each artifact creature you control, including the Overseer itself. The two-mana investment is modest, but repeated activations can make small utility bodies and tokens large enough to dominate combat or survive damage that would otherwise remove them.
Hangarback Walker and Walking Ballista are useful partners because their counters have additional functions beyond improving combat stats. The Walker can eventually produce more Thopters, while Ballista can spend counters on damage. Token makers such as Sai, Master Thopterist provide a wider collection of artifact creatures, increasing the value of each Overseer activation.
Untap effects multiply the output. Voltaic Key can ready the Overseer for another activation, and Unwinding Clock can provide opportunities during opponents' turns. In decks with blue, Dramatic Reversal can untap it alongside other nonland permanents. These combinations are most useful when you have several artifact creatures already in play, rather than asking one small body to justify the entire setup.
The Overseer normally needs to wait a turn before using its tap ability, so consider haste or protection if it is central to your strategy. Its counters remain after it leaves, which means even one or two productive activations can leave lasting value. Deploy your artifact creatures before activating when possible so the full team receives the counters.






