Kambal, Debt Collector

Kambal, Debt Collector costs {x} less to cast,
where X is the number of artifacts your opponents control.
Eminence: At the beginning of each player's upkeep, they may create 2 treasure tokens.
Only spend mana from treasure tokens to activate Kambal, Debt Collector's abilities.
{w}{w}: You gain life equal to the amount of artifacts
your opponents' control.
{b}{b}: Your opponents lose life equal to the amount of artifacts you control.