Hum of the Radix 
Enchantment
Each artifact spell costs 
more to cast for each artifact its controller controls.
Legality
standardNOT LEGALpioneerNOT LEGALmodernLEGALlegacyLEGALvintageLEGALcommanderLEGAL
Enchantment
Each artifact spell costs more to cast for each artifact its controller controls.