[Third person POV, Year 1999, Earth]
Time passed rather slow to the time-manipulator child; after all, having the power and using it to reverse time by loading his save file makes it so that he eventually tries to do different things.
'What would happen if I do this?... What would happen if I say this?'
The first years of its life were spent by our protagonist experimenting with its powers, testing the limits that defined them together with exploring in what universe he was, it looked like MCU as Robert DJR was Tony stark but because of news about mutants in tv made it weird to pinpoint exactly which earth he was in, so he decided to just discover first all of his powers, and proving if they aligned with what he knew of the humans from Undertale and Deltarune.
"So... let's recap a little bit," spoke Adrian out loud. He gradually started to develop this habit of saying what he was thinking out loud; after all, even if one of his parents heard some of his ramblings, he could always just load, and there would be no problem.
"Because I'm only four years old, I can't know exactly what would be the limit of my physical prowess. However, right now I can lift, with some effort, 90 kg of weight if my estimate is correct."
While speaking, Adrian was writing and drawing on a board that his parents gifted him so that he could let his creativity flow and learn to speak some Spanish that his mother was teaching him, as his parents already knew that his intelligence was one of at least a 13-year-old (loading the save file means infinite tries and infinite time).
"My loading powers are, for the moment, unmatched, as beings that usually mess with or are responsible for time haven't interacted with me or aren't able to find me just by loading the timeline as a whole." On the board were names of beings that had a relation with time, like:
Ancient One = No interaction. Probably knows of the shift in the power of time.
Loki GOT and GOS or TVA = No interaction. Don't exist or are incapable of interacting.
Kang or Variants = Can't time travel or don't exist altogether in this universe.
Mora = No interaction. Probably dead or freaking out about why she can't reset the timeline.
Dimensional Gods and Cosmic Entities = Probably noticed, probably can't interact...?
Then Adrian, with a light frown, quickly drew a stick figure stabbing a knife into the ground while smoke rose from it.
"The creation of dark worlds is something that I'm not sure I can do. Maybe it's a high-level application of Determination/power from UT and DT, like how injecting Determination in the flower that grew in Asriel's dust made it so he gets reborn as a flower. In this case, it would be injecting Determination/power through an object so inanimate ones gain consciousness. Maybe it's something unique to Kris that humans don't normally have and why they are probably not a known subject by the monsters in the light world. Regardless, this is a dead end for now. I'll have to study my soul to a deeper level."
Having said that, Adrian drew a large X over the previous drawing and proceeded to draw even more—this time, it was a heart and a musical note, while Adrian relaxed the frown he had.
"For some reason, I can, at all times and all places, make it so that music starts playing from nowhere. However, I have limited control of it, as I can only turn this on and off. Most of the time, when it's on, it plays music that fits with the current environment or situation. Although there are times I can change it to one that I choose in my mind. I know that music in Undertale is technically canon, as characters have acknowledged their own themes, but it's kinda weird that it fits with the situation and I can change it... Do I have a theme too?"
To test this, Adrian reached for his soul, and this one suddenly gave a faint red glow, only for music to start playing.
{Home from Undertale OST starts playing}
"I guess because I'm in my home and I consider it a secure place, this plays. Although I can change it, right now I don't understand the exact conditions for this yet."
Just before he turned off the music, the door was suddenly opened by Adrian's mother, who immediately directed her gaze at him and spoke:
"Why is music suddenly sounding if we are alone in the hou—"
Thinking quickly, Adrian turned off the music and decided to load his save file.
{Save file 1 loaded}
"Well, I didn't expect her to come so quickly... Does she have super speed and I don't know it? At least I saved before starting to write in this."
Adrian looked at the now-empty board and decided to stand up, walking to the door of his room and opening it.
'Oh, and having a good memory comes with the set too. Probably because to remember going back in the first place, my memories would have to be with my soul and not stored in the brain like a normal human, which is why I learned Spanish that fast (well, that and time travel shenanigans), as my brain uses that extra power to think faster.'
Slowly walking through the hallway that connected his room and the living room, our protagonist found his mother sweeping the floor of the hallway. 'So that's why she came so fast to the room.' He directed his voice to her.
"Mom, is it lunch time yet?"
The mother gazed in the direction of her son and answered his question while she kept cleaning the floor.
"Not yet. I haven't started to do it. Your father said that he will bring something from a Chinese restaurant."
Then, the day kept going like normal, and just like that, days passed. Weeks too, months alike, and even years were not spared until we finally came to the year 2001, the 1st of January, where our protagonist is found in his room scratching his head while looking at a large piece of paper with a pen in his hands.
"How the fuck do I stop one of the major acts of terror in the history of the United States? Even more when maybe Hydra is involved... This is going to take a lot of time."
'I can't save for at least 9 months or I risk making a mistake and saving over it... I guess I'll have to work with that.'
"Welp, this one is going to be a doozy."
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Author note: So, Our protagonist will start making some big splashes consciously, and how could it not be by saving thousands of lifes? Wouldn't you having time travel stop these events?
Oh, and i will explain some things, like the LV stat, you can take this as how much he is distanced of life and how easy would be for him to kill and bring himself to hurt others, this will be used in some plot points so please have it in mind.
I also put the musical power so that i could canonically put music that you guys could hear while the scene happens, and because it also happens in undertale it makes total sense :] not only that but it will have some plot related things with it in the future too lol.
Chapter is shorter than the one before because i want to use all my creativity in the next chaper, so drop powerstone and add to library please, btw King crimson is because of the time skip, if you are not a jojo fan.