Atomic Fire

Atomic Fire (アトミックファイヤー) is the special weapon obtained by Mega Man after Heat Man's defeat in Mega Man 2, Mega Man: Dr. Wily's Revenge, Mega Man: The Power Battle, Mega Man 2: The Power Fighters and Super Adventure Rockman. Proto Man, Bass and Duo can also use this weapon in the fighting games Mega Man: The Power Battle and Mega Man 2: The Power Fighters. Atomic Fire shots fireballs at enemies, and it can be charged to increase its range and power, being able to deal great damage when fully charged. If this weapon is used on Heat Man or Bubble Man in Mega Man 2, it fully recovers their health.

Capacity
In Mega Man 2, a normal shot uses 1 weapon energy unit, a partially charged shot uses 6 units, and a fully charged shot uses 10 units. In Mega Man: Dr. Wily's Revenge, a normal shot uses 1 unit, a partially charged shot uses 2 units, and a fully charged shot 4 units. In both games, Mega Man can't charge the weapon if there is less energy than required. With a full weapon energy gauge, Mega Man can fire 28 normal shots in Mega Man 2 and 19 normal shots in Mega Man: Dr. Wily's Revenge.

Bosses weak to Atomic Fire

 * Wood Man: Mega Man 2, Mega Man: The Power Battle and Super Adventure Rockman
 * Wily Machine: (1st Form) Mega Man 2 and Mega Man: Dr. Wily's Revenge
 * Plant Man: Mega Man 2: The Power Fighters

Bosses immune to Atomic Fire

 * Mega Man 2: Bubble Man, Heat Man, Buebeam Trap, Wily Machine No. 2 (2nd Form), Alien
 * Mega Man: Dr. Wily's Revenge: Bubble Man, Enker, Wily Machine (2nd Form)
 * Mega Man: The Wily Wars: Fire Snakey

Trivia

 * Atomic Fire was the first chargeable weapon from the Mega Man franchise.