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 shoots 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. It also can destroy Metal Blocks to get hidden power-ups, in Dr. Wily's Revenge.

Damage Data Chart
Known damage values in units for Mega Man 2.


 * *For Atomic Fire: the first digit is the standard shot, second is when it's charged more, and the third digit is when it is fully charged.
 * *Any data with a "+" represents the weapon actually restoring the boss's 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 (if he tries to fully charge with between 6 and 9 units, the weapon will stop charging and he will have to charge again to shoot a partial charge). With a full weapon energy gauge, Mega Man can fire 28 normal shots, 4 partially charged shots or 2 fully charged shots in Mega Man 2 and 19 normal shots, 9 partially charged shots or 4 fully charged 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
 * Flash Man: Mega Man: Dr. Wily's Revenge
 * 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, Boobeam 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. Its charging aspect is almost identical to that of the New Mega Buster, albeit takes longer to charge, possibly indicating that it inspired the idea for the Charge Shot in later games.
 * Atomic Fire is one of the earliest examples of a classic series' weapon to not resemble any of the attacks of its corresponding Robot Master, as Heat Man never fires Atomic Fire the same way Mega Man does, rather throwing arcing fireballs that grow once they hit the ground (similar to Flame Blast) and charging forward.
 * Atomic Fire has a charge like Heat Man's Aura does before a dash attack (though Mega Man is not invincible). The fireball is safer than the dash, hurling the "Atomic Fire" Aura forward.
 * Atomic Fire's charge is also the first to be lost by a hit. It takes both weapon energy and a little health.