Looks like those pesky Khans and dragons are at it again in the upcoming Magic: The Gathering set, Tarkir: Dragonstorm
I guess that goes right with the backstory
2 mana nets you a treasure token for every artifact and enchantment your opponents have on the battlefield, and since the effect is stapled to a creature, recursion and blink effects make its enter the battlefield trigger ripe for repetition
(7/15/2007) At the end of a subgame, each player puts all cards they own that are in the subgame into their library in the main game, then shuffles them
So, no you cant convoke and sac creatures for mana to pay for this
While going through an old hardcover journal from his high school years, he expected to cringe at the entries but was instead taken by surprise when a card tumbled out