Diamond Lion

The direct heir to Lion's Eye Diamond, redrawn for combo decks that wanted the original's burst of colored mana but hated staring at an inert artifact between draw steps. Both are permanents you hold on the battlefield until the moment you crack them, and both charge the same brutal tax: emptying your hand to float three mana of a single color. What the Cat adds is a 2/2 that can block or attack while it waits, so a dead draw at least has a pulse. The mana ability resolves without using the stack, so no opponent gets a window to respond to the mana appearing, but the floating mana is fully live while other objects sit on the stack: crack it in response to a spell to pay a tax like Mana Leak, or to fuel a Flashback cast once your hand is spent anyway. The discard cost dictates where that mana can go. Because activating empties your hand, the three mana can never pay for anything still in it; the payoff must already be on the stack, in the graveyard, or otherwise castable from a zone the discard does not touch. And the tap symbol in the cost matters too: a Lion freshly cast, or one already turned sideways to attack, cannot be sacrificed, so summoning sickness and combat commitments both gate when the ability fires. A creature that converts itself into a ritual on demand, priced for the deck racing a clock.