Dynacharge is a common Instant card from Return to Ravnica (RTR), collector number 92. Current market price: $0.18 (foil $0.50), TCGplayer market prices via Scryfall.
Target creature you control gets +2/+0 until end of turn. Overload {2}{R} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")