Kaleidoscorch

Converge measures the colors of mana you actually spend, which makes the front half of this card a self-limiting poke: a cast produces only one colored source, so a mono-red hand caps out at X=1 and even a wide manabase asking for two colors on turn two lands X=2. The effect is priced in manabase strain, not raw mana, and that is where the flashback flips the intuition. The recast is the only line that reaches the top of the curve, because those four generic pips can each be paid with a different off-color source, so a five-color spend from the graveyard delivers X=5. The back half is not a copy of the front; it is the version that can finish a game, since the front side's lone can only ever absorb one extra color while the flashback offers four slots to fill. The result is two burn spells sharing a card: a cheap, small sorcery from hand early, and a delayed five-mana bolt from the yard once the lands are online. It rewards a base that stays wide across the whole game rather than one that peaks on a single turn, which is why it belongs in greedy multicolor piles and does almost nothing in the aggressive decks that most want cheap reach. Converge and flashback pull the card in opposite directions, and the graveyard cast is where they finally cooperate.