Male reader x UNDERTALE [FINISHED]

Chapter 27: The plan

I was now standing in front of Gaster, I examined him but only his 'face' was visible, the rest of his body was hidden under a large black coat.

Y/n: What do you mean by 'little experiment'?

I heard a deep chuckle followed by statics as he seemingly teleported farther away.
I decided to follow him and as I was getting closer, I noticed that the pitch black void we were in started to change.
It went from black to white.

He faced me as I still wondered what would happen...

Gaster: I'll try to train you.

Y/n: Huh?

That's what he meant by experiment?

Gaster: Yes it is.

He can read minds?

Gaster: Yes

Y/n: Oh...

Gaster: You have many souls in you, but it seems that you can't reach for them.

I just nodded.

Gaster: The good news is, I can make strong, strong enough to erase her.

My eyes widened.

Y/n: You can? But I'm dead!

He just chuckled.

Gaster: Months ago, you could reappear when you died. I'm just saying that I can give you the power to phase through time and space. I can only go through space, I lack the soul to get through time.

Y/n: When do we start?

Gaster: Now!

He suddenly disappeared as I was seemingly thrown in the air at high speed.
I didn't have time to react as I landed safely in what looked like a living room with simple furniture. A couch, a carpet, a TV.... The list goes on.

Y/n: H-Huh?

He reappeared in front of me

Gaster: First off, I need to be sure that you are mentally ready.

Y/n: What do You mean?

Gaster: You see.... Chara learned to modify the games code so she'll trick you. I need to be sure that you are able to discern truth from lies.

Y/n: Hmm hmm.... And how are you gonna proceed?

Out of nowhere, he planted his fist through my stomach.

Gaster: Like that.

He stepped back as I feel on the ground, holding my stomach.

Y/n: B-bastar-

I felt nothing much...

Y/n: Huh?

I got up and inspected my stomach to see nothing out of the ordinary.

Y/n: How?

Gaster: I told you... She can now manipulate reality.... Sort of...

Y/n: Sort of?

He nodded.

Gaster: Yes, even if she broke through the code, there are still things that she cannot make.... Those things are sensations, like pain.....for now...

Y/n: For now....you mean that she's like...learning?

Gaster: Indeed.... Soon, she'll be able to be omnipotent...

Y/n: I see.....

He made a hundred of mirrors appear out of thin air.

Y/n: What am I supposed to do?

I heard a long chuckle.

Gaster: You need to find a mirror.

I looked around and obviously....I saw my reflection everywhere...

Y/n: Sounds easy...

I walked to a mirror and went to lay my hand on it but I just fazed through it and almost fell down.

Y/n: The fuc- ohhhhhh ok, I get it....

I roamed around, walking through some mirror that weren't mirrors... More like illusions.

After a long time walking and not finding a mirror in this mirror maze, I saw a weird reflexion... It was different from others.... It seemed.... Clear....

I walked toward it and when I tried to touch it, I was punched away in the jaw by my own reflexion?

I got up and looked in front of me.
Every other mirrors had disapeared by now and there was just.... Me in front of me......

Y/n: Whaaaaaa-

Gaster: You found the mirror! Good job, you now have to fight the man in the mirror.

Y/n: Fighting myself huh?

I ran to my reflexion and threw a punch at it when it suddenly stopped myself.... It was not my reflexion anymore, it was Toriel.

Y/n: T-Toriel?

Gaster: Naive.

Toriel punched through my stomach and I was sent back.
I checked my stomach to see no real damage...

Y/n: Damnit....

Timeskip:

After getting my ass kicked for what seemed like an hour, I finally managed to see through illusions.
I layed on the ground, exhausted as I was transported back to the room from before...

Gaster: Well done, you can now see the truth behind lies.

I panted.

Y/n: Nice...

Gaster: It also seem that you have woken up the souls that were sealed in you long time ago...

Y/n: Huh?

I sat up, looking at him, confused.

Gaster: Because of that, you were able to pass the first test.

I sighed. It was taking a long time, and I don't think that I have much to spend anymore.

Gaster: Don't worry about that. I have a plan to give you the chance of beating her before she gets too powerful.

Y/n: And what is that plan?

Gaster: That plan is.... The second and last test.... To survive sharing your soul....

A/n: LAAAAAAATE HAHAHA, sorry, but the chapter's here and it took me some time to get the ideas right XD. It hard when you know the plot but you don't have a clue how you'll write it.
Anyway, thanks for reading, see ya!