(Crack. A piece of the heart has been severed off.
The switch has ceased hanging in the middle. All that is left is
down,
down,
and further still.)
By the time Deku's mind had returned to the surface amidst the turbulent thoughts, he was already in front of the gym. It was best described as a concrete cage, with large billowing walls that didn't let a single speck of light inside. If it weren't for a rusty old sign declaring to the world that it was, in fact, a gym then no-one would believe it. Yet even then, this place didn't have a single (normal) visitor.
Deku dragged his feet over to the very edge of the building, before going to the right exactly 13 feet. He lightly pressed down on the slick concrete, and the mechanism activated with a click. The wall slide to the side, revealing a passcode. He continued to tap the '6' four times.
"Sometimes I wonder about his taste, to be honest." Deku uttered apathetically.
Seconds later, the concrete slid away to reveal a unlocked door. The door flew open with a whoosh. It flew open to reveal All for One (with a side dish of Zero, of course).
"How are you feeling, Izuku, or would you prefer Deku?. How are you feeling?"
His only response to that question in particular was a glance of apathy.
"I won't bother to ask how you know about that name. I only ask you this; did you purposefully decide for me to kill that woman, employer of Zero?" he continued onward with his words, despite the slight surprise of Zero and the growing amusement of All for One, "I know for a fact that Zero only does his job, it would be illogical to assume otherwise. Why then would he make me kill his supposed target? The only answer is that it was never his target. She was mine."
All for One coughed out a rather raspy chuckle.
"And why do you assume it was me who did it? Couldn't it just have easily been someone else who lined his pockets with money? Surely despite your short time with him, you've seen his appreciation for the commodity."
"I take offense to that!"
Deku's eyebrows slanted downwards, as he added the slightest bit of pressure to his gaze. Not too much, nothing good came from pushing the man over his limits. But if he thought he was losing his calm... That was something that he could work with. A creature of impulse is easiest to control as creatures of impulse all react the same when certain buttons are pushed down. The underestimation could work in his favor in the long run.
"I don't believe in coincidences! He couldn't have just so happened to get hired in such a manner right in the middle of your test!"
That was the truth, the frustration not so much. He had come to a realization after the incident. Before he couldn't experience emotions in an 'overboard' manner so to speak. He still had deep-seated desires to feel, and some extreme situations could dredge the emotions out of his soul. Now, however... It was like a switch had just turned off. He couldn't honestly care less anymore. Everything was dictated by logic.
Revenge is necessary, therefore take steps to complete it.
Being a puppet is not ideal, therefore make contingency plans.
Just like that, Deku lost his humanity.
"You're right, Deku. It was indeed me who ordered Zero to behave in such a manner. I don't believe that this changes anything though?"
Deku acted as if he was reining in his emotions.
"No, it doesn't change anything."
He lied this time. In truth, it changed everything. According to the pieces of his moral compass that were still intact, in this situation since he can't take care of the committer, which is himself right away, (he could kill himself later, revenge was still a thing after all), he could only kill the mastermind. Although he couldn't quite tell how he was going to achieve that as of yet, the board was not yet set in stone. Victory was still possible.
"Good, seeing as you have passed all of my tests... It is now time to give you a quirk."
Those words succeeded in capturing Deku's full attention. After all, the quirk would beef up his chances quite a bit.
"I have looked through my collection, and decided this quirk i.e. 'Green Lighting' is most suitable for you," All for One paused slightly, "As much as I would like to give you an information type quirk... It is better not to, considering your mental condition. Your brain may react adversely to the stimulus."
He aligned his features into what would qualify as a faint smile, as he crunched the numbers in his head to determine how exactly he could integrate this into his plan. He still paid attention to the outside world, however. At All for One's beckoning hand, he drew closer. Then the hand of All for One rested upon his scalp, and the process began.
His pain receptors were alight with flame, his body was thrown into haywire as his genetic structure began changing, and his limbs began twitching erratically, but Deku once again didn't care. He faced it like an outside observer peering in, not caring the slightest as to the pain he was going through. All aspects of his being were focused on feeling out the process. Of course, for his little audience, he didn't forget to look in pain.
Suddenly, One for All looked onward in shock.
"The quirk... is mutating?!"
As the quirk finished embedding itself into the genetic structure, it turned towards the brain. That was when it started to change. Dark green, grayish-green, grey, and finally a deep gray color. It swam through the air for a little while longer, before diving underneath Deku's skin.
"It still retains its' base form, but the color changed? The color green is associated with safety, harmony, and balance... Could it be that the meaning associated with it was simply too different, to the point where it adapted? Grey is considered unemotional and detached. The perfect fit! Hahaha, instead of being devoured by the quirk, he forced it to fit himself!"
As the last little bit of lighting fizzled away, All for One looking down upon him with a demented smile.
"How is it?!"
"Never been better."
"And all of a sudden, I knew somehow that I was hollow. Twisted. Deformed...
Like all of the pure souls the world had converted into rotten soldiers,
they too had warped me into something not quite human."
-Deku