"In a world where Death is the hunter,

there is no time for regrets or doubts.

Only decisions."

-Carlos Castaneda

'...As I thought, the real challenge is only beginning. I can distract Kurogiri and Shigaraki easily, but All for One... He is a man with both intelligence and experience. I can't reach an in-depth conclusion from my limited interactions with him. Furthermore, I don't know much about his personality beyond the bare basics. I can only go with the flow and play it by ear.'

"You know about my quirk, correct? I can only assume that this was an ability gained by its' mutation, but..."

A laugh suddenly resounded out of the screen. It was inexplicable, diabolic, and coated with a touch of capricious amusement. Like a cat on the prowl that had caught a particularly peculiar mouse. It didn't bother to eat it right away, for no matter how much it pleaded for mercy, or how much it raced and fled, it would still be holding its' tail.

Deku's mind raced as he pondered over each and every word he had uttered. Nothing struck him as out of the ordinary. He hadn't even gotten into the 'meat' of his reason. There was nothing contradictory about it at all! All he had talked about was the quirk that the man himself had given him...!

'What if he can detect lies? Damn it, I didn't think about this... I wouldn't put it past him to have a mind type quirk in that little stash of his. It should only be a lie detection quirk, though. Primarily because of their rarity, and also because he hasn't made a single reaction to my thoughts! If he knew I wanted to kill him, he would eliminate me as soon as possible. He wouldn't dare risk his plans to that degree.'

He made a faint thoughtful noise.

'The only reason why he's playing with me now is that this is, ultimately, a small issue. Well, for him anyway. Shigaraki would probably take the opportunity to make me a de facto slave. Or minion. I can only foresee that route ending in my eventual death via a suicide mission. On second thought, that doesn't actually sound that bad... Maybe after I kill All for One. I'm sure Shigaraki wouldn't mind.'

He mentally slapped himself to get himself back on topic, knowing that his silence was starting to look less like thought and more like stalling purposefully. Still, he couldn't stop himself from thinking one final thought.

'I haven't actually said anything wrong yet, so there's still a chance. In fact, this approach could work better than the other one I thought up! As long as what I say is technically true,-'

"Well, it may just be my own personal judgment. I haven't been able to fully explore the limits of my quirk, to be honest."

The laughter stopped.

"When we were all watching Nomu fight All Might, I got a feeling. I knew at that moment, with perfect clarity, that he was going to win. And shortly after, my quirk backlash happened. I left the fight hurriedly, but I also made sure to tell Kurogiri to give everyone portals to jump into at a moment's notice."

'-I can mix up the timeline. Everything's technically true, after all.'

"...You still left the fight. What if Shigaraki and Kurogiri were killed as a result?"

His tone was no longer lighthearted. It was serious and pondering as if a cat had been chasing a mouse, only to find out that the mouse was a cat instead. Even through the buffering of technology, it was impossible to hide the slowly increasing intent behind each word. Not something malicious, nor was it killing intent, but something different...

Something like anticipation.

"With all due respect, Sensei, even if I stayed at the fight, I wouldn't have been able to do anything. We are facing All Might, after all. Even Nomu was no match for him. Besides, if I stayed there only for my quirk to act up, I likely would have become the baggage that caused their death. I believe that a strategic retreat was the best option that I could have possibly took."

The small bar was drenched in silence, as only the small beeps of a heart monitor remained. Kurogiri seemed content to let the subject rest, while Shigaraki looked like it was taking all he could to hold it in. The only likely thing keeping him in his place was his respect for Sensei. Deku had not registered any of this, too busy thinking. In truth, there were many spots that he barely skirted out of. If luck had not been on his side, if he hadn't realized that All for One had a lie detection quirk...

'The only reason I won against All for One is that I had the situation on my side. He has witnesses for this whole thing, so he can't just torture me for no real apparent reason. Plus, if my quirk didn't give me backlash, my argument would have lost a whole lotta bite. I didn't expect him to have such up to date information right away, nor did I expect him to interfere. Doesn't he still want to groom him as his successor? Why didn't he let Shigaraki do it as usual?'

'I need more information, in the end. This all happened because I don't know his personality well enough.'

The cough of All for One made all of the occupants of the room stand alert.

"...Your reasoning is sufficient, Deku. I will not punish you, this time. Please keep in mind that such reasons will not work twice. I am not fond of cowards. But your actions are not motivated by death, but by rigorous logical thinking, so I will make an exception this once," All for One gently nursed the cup of tea in his hand, as his lips drew up in an evil smile fitting of the man nicknamed 'The Symbol of Evil'.

'Our game of chess is not quite over just yet, Deku. You have won the first battle, true, but there is still the whole war left to wage. Ever since the day you came back, you were overflowing with killing intent towards me. Normal people wouldn't have noticed it, you did a very fine job hiding it, but no-one can hide from quirks. I thought about killing you just then, but there was something about you that promised to be amusing. A challenge, I even dare venture. In a bout of insanity, I gave you that quirk.'

He couldn't bring himself to repress his laugh at that daredevil move of his. There was a very high chance that the boy's ego would just die out upon the completion of its' evolution, but on the off chance he survived it... Well, there was a reason it was among the best in his collection. Even he had not dared to cultivate it even with his many resistance type quirks.

'Will you be my undoing or will I inevitably kill you? Ah, it's very exciting indeed!'

AN: All for One doesn't have much screentime, and I decided that he didn't have very much 'personality' during the short time periods he had screentime, so in this, he's a maniac immortal that hasn't tasted defeat in ages, so he craves it. He really, really, wants a good challenge. Kinda like Aizen.

You people told me that you liked psychological warfare, so I put more of it in (with a much smarter/experienced big boss villain, so it hopefully feels suspenseful). I also hope the conclusion of the 'fight' was realistic in your viewpoints.

Please continue to hit the hearts and give me constructive criticism in the comment section~!