Acceleration Blast is an incredibly powerful firing mode for the main cannon of several Sophia iterations, typically used to destroy especially powerful mutants with a massive beam blast. Debuting as a cutscene weapon at the end of Blaster Master: Blasting Again, it becomes somewhat more prevalent in the Zero duology.
In Blaster Master: Blasting Again the Acceleration Blast is the final attack used against Kaiser after defeating him through conventional means. Sophia J-7 undergoes a transformation that basically locks it to the ground and activates an enhancement to the cannon. It is evidently fueled by all the emotions that Roddy has because his mother tells him to pour all of them into the Acceleration Blast, saving Elfie and defeating Kaiser.
|“||Release a huge amount of energy to attack. SOPHIA's most powerful weapon. Hold the Shoot button to charge it, then release to fire.”|
|— Acceleration Blast • Blaster Master Zero|
Acceleration Blast makes its first appearance as a gameplay-usable weapon after being obtained from Venom Master in Area 7. As an alternate firing mode for SOPHIA III's main cannon, it fires normal cannon blasts when the Shoot button is tapped, and requires a full SP bar to use its actual effect.
Holding the Shoot Button while on a floor (not a wall or ceiling) for an initial ~0.75 seconds to actually charge the weapon begins an animation sequence, taking 1.25 seconds to complete, where SOPHIA III deploys ground locks and transforms into a massive cannon. The SP bar changes from a notched meter to a continuously filling bar while charging for 4 seconds; no SP is consumed if the charge is released prematurely by ceasing input or taking damage. Successfully charging and firing the Acceleration Blast, which occurs ~0.7 seconds after releasing the Shoot button on a fully-charged bar, fills nearly the entire screen in SOPHIA III's facing direction (and a large distance beyond the screen's edge) with a colossal laser shot for ~3.2 seconds, granting invulnerability for the duration while destroying blocks and red crystals, dealing massive damage over time, and draining the entire SP bar. Once the SP bar has been depleted (or if the attack is manually cancelled), SOPHIA transforms back into its usual form over another ~0.75 seconds, after which movement and sub-weapons are enabled once more.
Acceleration Blast's total damage output over its ~3.2-second duration is the same as 97 Blaster Rifle shots, and it is capable of destroying blocks and spikes by default, not requiring other upgrades like Crusher Shot.
A variant of Acceleration Blast is installed on Sophia Zero, which has the same SP requirements to fire, but gains a quicker setup animation (~0.5 seconds long) and charges to full power twice as fast; in addition, taking damage while charging no longer cancels the attack. This Acceleration Blast is 20x stronger than SOPHIA III's, dealing 1940 Blaster Rifle shot damage over its duration and is capable of instantly destroying both Central Gear and Ribbiroll on the first damage tick.
A scripted event is triggered, with additional dialogue playing in Normal and Destroyer modes, if Acceleration Blast reaches full charge in Area 7 while in the same room as Skeleton Boss, regardless of whether SOPHIA is actually aiming at the boss mutant. When the attack hits the boss in modes other than Destroyer Mode, blast damage over time is adjusted such that it always destroys the boss ~2 seconds into the blast, even if it should die much sooner (as would normally be the case in Unlimited Mode). In Destroyer Mode, however, Acceleration Blast will only deal its standard damage output, taking off less than 10% of Skeleton Boss's HP bar rather than destroying it in one shot.
Invem Sophia is able to use its own variant of Acceleration Blast up to 2 times during its boss fight, based on the game mode; as well, the player is able to use Acceleration Blast against their opponent in Blaster Battle Mode while playing as Jason in a side-view battle. In both cases, a SOPHIA model caught in the blast will lose 1 health per ~0.5 seconds unless it manages to escape the blast by moving behind the caster.
Gaia-SOPHIA does not possess the Acceleration Blast, but can emulate its effect with the Full Accel Burst Sub-weapon. Weapons with identical effects are employed against the player by Atom and Dig-Rawler.
|“||Unleashes energy at ANDREIA's maximum output. Press [Jump] repeatedly to charge and fire... But, due to damage to ANDREIA's frame, it is currently locked.”|
|— Accel Blast • Blaster Master Zero 2|
The Acceleration Blast nevertheless appears again in Area Ω when Eve, separated from Jason after the defeat of Planade-G, discovers Andreia and finds it installed aboard that Metal Attacker, but in a locked state. Confronting the Mutant Cocoon (and true final boss of BMZ2) Drolrevo, Eve unleashes the Acceleration Blast with covering fire from the three allied MAs summoned by the Emblems and an ambiguous "Purification Energy" channeled through I-HIX. It is used in cutscene form, with the perspective shifting to first-person from Andreia's cockpit.
This Acceleration Blast is able to save Jason from his petrification and cure Eve's own corrupting body, though it is unknown why this is the case. Eve assumes this effect was added due to her fueling the Acceleration Blast with "purification energy", an exact reason, however, is not given. It is also assumed that Andreia is either totaled or rendered otherwise inoperable after the attack, given Eve's lamentations to that end in the final Talk conversation as Jason and G-SOPHIA face off against Drolrevo Mastro.
|“||Jason: So this Acceleration Blast lets SOPHIA use all of its power in one concentrated, super-powerful blast, huh?
Eve: It won't fire unless your SP gauge is maxed out, but make no mistake... it has tremendous power. However, using it can be quite a burden in a number of ways...
Jason: Looks like I'll have to use it only when the timing is right.”
|— Acceleration Blast (First Talk with Eve) • Blaster Master Zero|
|“||Eve: ACCELERATION BLAST: With this main weapon, you can hold down the Shoot button to charge a shot, then release it to fire.
Jason: This is SOPHIA's most powerful attack, right? Looks like it'll use up a lot of energy.
|— Acceleration Blast (Subsequent Talks with Eve) • Blaster Master Zero|