About The Final Charge

The "Final Charge" is the extra-large buster shot Mega Man fires at the end of the Power Gear charge. It is most commonly seen in casual play when using the Double Gear Technique. 
 It does 8 damage and pierces/Passes-through all enemies(?). Without the double gear, firing this shot immediately over-heats the Double Gear system. 
 Charge Time 
 Without Double Gear, the Final Charge shot usually needs the entire time-limit of the Power Gear to build-up, and you only have a short time to fire it before over-heating. 
 In two scenarios, the Block Man fight, and the final room of Bounce/Rubber Man, this requires tight timing to get your short fired at the right time. 
 For another, the Pickman Digger mid-boss of Impact Man,  the charge continues building while Mega Man walks through the door, even though the gear's time-limit does not proceed towards overheating during that time.  This makes it a little easier to time a hit and get the extra damage from the shot.