All Might sat neat to your bed, clasping his hands together, unsure of what to do or say. The silence made you wake up slightly from your pain-killer-brain-numbness.
'W-wait! I mean, I don't- I- ugh.' You stammered, now not really wanting to share secrets.
All Might furrowed his brows, wondering how to address
this problem at hand.
'You see, young LN- when I was fighting, you sent black fumes my way, now I assume this was because you somehow knew I was at my limit of my transformation. But the problem- the problem is- that I was frozen the second the smoke hid me from view.'
'What?!' You asked incredulous.
'Not mentally, I was physically stuck in the the spot.
———
Fume of the Etherious YN LN.
In the pit of the demon's stomach, devoured atoms and etherano churned together. Depending on the demon's fury, the chemicals become more toxic, and dangerous elements clash- think of a factory. Once the anger fume has been ignited, smoke billows out. This smoke is one of Etherious YN LN's attacks, not that she remembers much.
———
'Now I gained this injury ages ago, in a massive fight. This limits my time in buff form, think of it like the guys puffing up at the pool to impress ladies. By the way, how did you recognise me? Not much people can...'
Oh? Could you trust this man about the secrets you've hidden since the day you came to this world?

'Well-I -I-I...' you trailed off, now cursing yourself for even hinting you had been hiding any secrets. 'I don't know how to say this... after all, I am hiding a lot...' What?! No! That will make him more curious! Stupid drugs!

'Start with your quirk.' All Might, suggested. 'On your enrolment form, it said your quirk was called unknown, and it was a unique quirk. But you seemed to know a lot about it yourself, could you explain it to me?' All Might hoped he didn't sound too cold, but the second he saw you stiffen up, he knew he was onto something. As mean as it sounds, if you were a threat, then you would have to be monitored more carefully.

OH SHIT HE'S KNOWS HE'S ONTO SOMETHING!

Panicking internally, you struggled to get into a better sitting position.

'Ok, so... I won't tell you everything but I can assure you I am no threat.' you started off carefully, for the first time choosing your words. 'But you must not tell anyone including your fellow colleagues.'

All Might considered this and nodded.

'So, my quirk- you can't really call it a quirk, I guess.' You started, All Might interrupting you.
'What do you mean!?'
'Wait I'm talking!' A tick mark appeared in your forehead.
'My quirk, allows me to eat anything and immediately digest it, turning it into my own power.' You tried to use the smartest words you could think of at the moment, and All Might muttered to himself.
'The absorbent type? But how is it not a quir-'
'I'll get to that later. But, I am immune to everything I've eaten- well for a long time at least.' You explained. 'Back where I come from, it's called Dragon slaying.'
'Dragon slaying? How is that related?'
'This quirk, as you guys call it, made to-  oh wait I can't tell you that.'
'LN...' All Might looked at you.
'Look, nothing dangerous! It doesn't even exist here!' You exclaimed, how on earth where you gonna convince him you were raised by a DRAGON?!

'Ok,ok sorry, continue.' All Might sighed.

'Uh so secret two! I'm actually partially physically dead!' You tried to make that sound not weird, but you failed.

'What!?' All Might looked at you as if you had gone insane.

'And I'm one third demon and one third dragon?' Now you were confused. You had kind of grown used to the ways of this world, and even the truth sounded weird to you.

'And I'm not from around here, like at all.' You scratched your head wincing from muscle pain. 

'Not from Japan?' All Might looked at you.

'Think bigger.'

'Not from Asia?' 

'Bigger.' 

'Northern hemisphere?'

'Bigger.'

'Then what?' All Might asked, frustrated.

'I've told you too much, All Might. Now that I know your secret, and you know mine, you cannot tell anyone, including Mr Aizawa. I promise you that I am no threat, and I don't have any ill wishes on anyone. With that in mind, I will keep your secret safe.' Your eyebrows furrowed after speaking for such a long time.

This was definitely a spin on your usual happy-go-lucky personality.

You yawned and snuggled back into the bed, and instant sleep hit you.

All Might walked out, Aizawa looking at him expectantly. 

'I promised not to tell you.'

'What-'

'She is no threat.'

As Aizawa walked away, All Might muttered to himself,

'Although that doesn't make this situation any less confusing.'