Decadent Dragon // Expensive Taste

The Adventure half is theft dressed as card advantage: it exiles from an opponent's library rather than their hand or board, and the "for as long as they remain exiled" clause leaves an open-ended window to spend the loot. Because the top of a deck is random, this is not resource denial in any precise sense; it does not pluck the answer out of their draws, it just hands you two extra cards to work with. The spell leaves one problem unsolved: you have to produce the colors those stolen cards actually cost, and nothing on Expensive Taste lets you spend mana as though it were any color. That is the seam the Dragon is built to close. A 4/4 flier with trample that mints a Treasure on every attack is a color-fixing engine as much as a beater, and each attack builds the pile of Treasure that turns the odd off-color card you pilfered into something castable. The two halves want opposite timing: cast the instant early, before you know what you will steal but while you still have turns left to burn the exile away; the Dragon is the follow-up whose combat clock does double duty, pressuring life totals while manufacturing the fixing that unlocks the theft. The mana split carries the flavor: black pays for the larceny, red pays for the wings that bankroll it.