Zane, the Door Goblin

Artifacts you cast cost {x} less to cast where X is the number of artifacts you control with charge counters on them.
Whenever you cast an artifact spell with mana value 5 or greater, put a charge counter on target artifact you control.
{u/r}: Remove X charge counters from an artifact you control: Deal X damage to any target.
"Come, come if you please, but beware if you have no cheese." —The Door Goblin