Loop Crystal

Loop Crystal enters the battlefield with a charge counter on it. When a spell or ability activates
a combo of abilities that never ends (for example drawing a card which activates an ability to create a
token which activates an ability to draw a card, etc.)
you may remove a charge counter from Loop
Crystal. If you do, interrupt that combo, remove
all effects from the stack, and exile one card that contributed to that combo.
Equip {4}