//God I made Gaster so OP it’s ridiculous, so his abilities if anyone curious
Bone Bullets: What it says on the tin. He typically doesn’t use them very much.
Gaster Blasters: The originals, they can grown to a ridiculously large 16 ft tall and can divide, though they do lose power if done.
Damage Control: Like Papyrus he can control how much damage his done to HP, though this does not take away the pain of the attack, such the laser of a Blaster
Void Being: He’s pretty much immortal as far as pretty much anyone is concerned, the most you can do is hammer away at him until he can’t hold his form any longer and has to return to heal in The Void. It has also turned his body into a melting mess of Magic, Determination, and Void...ooze. That cannot feel pain in the same way most people do and it helps in a fight, though KR does hurt in a more normal way and cause him to burn and bubble and is a very easy way of getting rid of him compared to normal damage. He can also change the shape and form of his body, to either harden and sharpen his hands, to say, rip through someones chest, or to make himself look similar to his old life.
High LV and near SOULlessness: He is one with very high LV due to, countless murders of humans who fell outside of the main six that are scene normally. This was at first due to attempting to stop his Flowey from gaining the power, he also began devouring the SOULs of the those he murdered. He is also nearly SOULless due to the destruction of his Timeline which contained many shards of his SOUL were wiped out by it, leaving him a small sliver of his own, combining with his high LV a monster who is very likely to do terrible things without care whether they are abhorrent or not.
Human SOULs: He has consumed countless SOULs in his life, some during his time in The Underground to keep them away from Flowey, but even after he know longer needed to he felt the...need to have more and has since gone on many trips to find suitable SOULs to devour, they dont give him the same boost as to make him like Omega Flowey, but has still made him incredibly strong along with his high LV, they mostly helped him stabilize his form so he can visit longer in reality, but also granted him great power as well
Determination: Originally before he fell, he was the only ‘monster’ with such high Determination for a time and was able to use the SAVE and LOAD abilities, though he never tapped into RESETs, he mostly used them to make sure any projects he had went according to plan after he fell he was no longer able to access these abilities but Determination was used to save him from complete annihilation. Along with...
Perseverance: An ability used many a time by him, to continue to strive forward long after he should be able to and paired with Determination it was a powerful weapon in his hands, allowing him to escape death, not once, but twice.
Glitching: His body at times can face many glitches he can and cannot control. As his Shortcuts seem to be him simply forcing his way through rather unpleasantly instead of simply disappearing and reappearing as Sans does. This also leads to those being unable to CHECK him or his STATs, at the most, being able to see his name in varying forms, Wing Dings included.
Code Manipulation: He can change the code in worlds that resemble his own. Mostly using it for simple things, but he can change things drastically. Such as literally stealing the RESET button of his Timeline and making all SAVE points eyes he can use to observe any who uses them, rare as that maybe.