Billionare Oil Barons!

Enchant Target player. As this enchantment enters the battlefield, choose a color.

Whenever enchanted player spends mana of the chosen color, they must either pay 1 life for each
mana spent or give you an equal amount of mana of the chosen color.

"Petroleum absolutely brings wealth to society.
And there's no greater evil in the world than poverty!" -Shion