The Mega Buster can be leveled up in three different categories:
- Attack -- Increases the potential damage the MB can deal. Formula: [Level] x 
- Rapid -- Increases the MB's rate of fire, especially at longer distances. Does not affect charge time. Formula: At a very long distance, one extra shot per second. So [Level] = Shots per second.
- Charge -- Decreases the amount of time needed to charge the Mega Buster. Does not affect the damage done in question however. There are large differences in charging from game to game as well.
At the beginning of each game the Mega Buster begins with these statistics:
- Attack: 
- Rapid: 
- Charge: 
The maximum stats:
- Attack: ()*
- Rapid: 
- Charge: 
- Attack doubles with the addition of a Guts/Hub Style in the second and third game, at the cost of minimalized rapid.
- Charging can only be performed from Charge Level 2 onwards.
- There are two types of charge shots: A quick "green" charge and a powerful "magenta" charge. A green charge will typically hit for about 8x the normal shot. 2 attack would equal about 16. A magenta charge will typically hit for about 16x the normal shot. 2 attack would equal about 32.
- Of all the games, the first has arguably the "fastest" MegaBuster.
Upgrading is similar to the first and second game, using Power Ups. At least 1 Charge is required to use charge shots, while Max charge will allow for quick charging to level 3 shots. Shots are similar to the X-Buster.
- The green charge is removed and replaced by the magenta shot. It hits for 5x the normal shot in BN2, and hits for 10x normal in Mega Man Battle Network 3.
- Charging can now be performed at Charge Level 1 from Mega Man Battle Network 3 onwards.
- "Normal" rate of fire is slightly lower than the first game.
- Style Changes allow for various elemental charge shots. The damage output is fixed regardless of Buster attack power, but they can be upgraded through Levelling up the Styles or use of Navi Customizer parts.
- Heat: A 3-square flamethrower akin to FlameMan.EXE's. Medium length Charge, longer than normal buster. Hits for 50 (LV1), 80 (LV2), or 100 (LV3) damage.
- Aqua: A bubble shot akin to the Bubbler chips, hitting the square behind. Fastest Charge, but charge times between BN2 and BN3 are considerably different. In BN2, hits for 30 (LV1), 40 (LV2), or 50 (LV3) damage; in BN3, hits for 40 (LV1), 60 (LV2), or 80 (LV3) damage.
- Elec: A paralyzing "zap" similar to the Zapring chips. Long charge. Weakest attack, but offers a paralyzing effect. Hits for 20 (LV1), 30 (LV2), or 40 (LV3) damage.
- Wood: A windy dust devil sent 2 squares in front of the player. Hits 8 times. In BN3, with the addition of Sand panels, the buster will deal twice as much damage to enemies on Sand panels. Medium charge. Hits for 10 (LV1), 15 (LV2) or 20 (LV3) damage per hit.
- Guts style: Attack stat is doubled for a maximum of 10 but the Rapid stat is forcibly set to 1. In MMBN3's Guts style, when the player taps B rapidly, the Guts Buster turns into a machine gun and fires off about 8 rounds. In theory the Rapid stat is increased to 8-9 for the duration of those 2 seconds. Example of a "maxed out" Guts buster.
- MMBN3 Blue's Shadow style: The Mega Buster creates a cloak of invisibility for its charge shot, firing off no projectiles. The effect lasts 2 seconds and cannot be extended. If a WepLv+1 NCP is installed, the charge will be that of the style's element.
- MMBN3 White's Ground style: The Megabuster's charge shot has a panel cracking effect, determined by the style's element.
- Heat styles will always crack the 3 panels it covers.
- Aqua will crack the panel it hits along with the immediate panel behind, if it connects.
- Elec will crack the panel it hits if it connects.
- Wood will destroy the panel it covers, regardless of whether it connects or not.
- Mega Man Battle Network 3's Bug Style: Mega Buster effects range from straight 5 stats to straight 1 stats. This is random.
Mega Man Battle Network 4 and beyond
- The Mega Buster's rapid fire is seriously toned down.
- Styles like Guts are no longer present.
Souls and Crosses
Double Souls grant new appearances and charge shots for the Mega Buster. In Mega Man Battle Network 4, Attack and Charge Customizer programs have no effect on Unison charge shots, being pre-set. In Mega Man Battle Network 5 and 6, Souls and Crosses have charge shots that are dependent on Buster attack strength. Buster limits can be broken in 5 and 6 thanks to the Busterup chip.
Mega Man Battle Network 4 elemental Double Souls like ThunderMan.EXE have charge attacks identical to the old style changes.
Invoking Beast Out in Mega Man Battle Network 6 also changes MegaMan's Buster. Holding down the B-button no longer charges the Buster for a charge shot, but instead allows MegaMan to fire his Buster continuously.
Beast Out Gregar: MegaMan gets a Gregar Buster that fires very quickly down the row he is on. Possesses perhaps the fastest firing rate in this series.
Beast Out Falzar: MegaMan's rapid-fire Buster is a little slower than Gregar's, but in addition to covering the entire row he is on, it also hits 3 panels down the rows beside him, starting from the panel immediately above or below him.
In Mega Man Battle Network 5 and 6, the Battle Chip Buster Up (バスターアップ?) increases the attack power of the Mega Buster by 1 point.
Mega Man Battle Network 5
|Standard Chip 159||BusterUp||Power goes up by 1||*||5 MB|
Mega Man Battle Network 6
|Standard Chip 177||BusterUp||Power goes up by 1||*||11 MB|