The top right corner is the 'cost' that a player would need to spend to summon a Black Knight (two black mana from Swamps, in this case)
This archetype is especially strong when artifact cards are not only for the artifact deck. A good artifact creature can be aggro filler, sacrifice fodder, blink material, or equipment carrier
Now that we know Infinity Constructed is being well supported, staples like these may well retain a good deal of their price
Shared Animosity works with any of these typal strategies and amps up your attack power immensely
Spinning Wheel Kick Spinning Wheel Kick is a stretch because it still targets and suffers from the cost a lot more than many of green's board wipes because you need to pay per target
In longer chains, it acts as a Narcomoeba/Prized Amalgam hybrid can both trigger our 3/3 and its a somewhat threatening body on its own