This story ended up being very long so I split it into two parts.
Requested by stanforbabyblue234
Tokoyami and hawks were on patrol when they came across a fairly new villain. There isn't much about this villain beside saying that in order to change a person, you must change the person's past
Tokoyami: Senpai, watch out.
Hawks: huh [gets hit by a quirk]
Tokoyami: Senpai
There was a blinding light
Few minutes later
Hawks: what happened
Tokoyami: ...who is that senpai? [ points at the little boy that looks like he could be hawks's son]
Hawks: ...
???: w-who are you?
Hawks: I'm Hawks.
???: K-keigo...m-my name is K-Keigo.
Hawks: Hi keigo. I'm a hero.
Keigo: H-heroes don't e-exist.
Tokoyami: I'm Tsukuyomi. I'm a hero in training.
Keigo: h-hi
Tsukuyomi: Heroes do exist and the one next to me is a hero.
After putting handcuffs on the villain, Hawks turn to his kid self
Hawks: let's get you check-
Hawks: !?!?! where did he go?
Tsukuyomi: what do you mean? he's right over-
Somewhere in else, dabi was sent out to get supplies
Dabi: so annoying
Keigo: [wandering around and accidentally bumps into dabi] s-sorry
Dabi: ??? [looks down and sees Keigo] what's a kid wandering around near here
Keigo: I-I
Dabi: [couches down] are you lost
Keigo: ...
Dabi: ...let me show you something [lights his hand up making little designs with his blue fire]
Keigo: [instead of being scared, he was memorized] pretty [tries to touch it]
Dabi: [notices that the kid tries to touch the fire, pulls his hand away] don't touch it unless you want to get burned [extinguished the fire]
Keigo: [pouts] it's pretty
Dabi: [snort, smiles a bit] you're an odd kid [his staples shining in the light]
Keigo: shinny [grabs dabi's hand to stare at the staples] pretty
Dabi: ... [tries to pull his hand away] kid-
Keigo: no [clings to Dabi's hand] mine, pretty, shinny thingy
Dabi: maybe I can throw you at some hero
Keigo: no, don't leave
Dabi: Kid, I'm not safe-
Keigo: No, stay with me
Dabi: I-
Keigo: please
Dabi: ...fine
Keigo: [clinging to dabi's hand]
Dabi: what do I call you?
Keigo: ...
Dabi: I'll call you brat
Keigo: no
Dabi: how about phoenix?
Keigo: ...na-uh you first
Dabi: me first wha- oh...Dabi, call me Dabi
Keigo: K-keigo
Dabi: Keigo huh. Let's head to where I'm staying
Keigo: [grasping onto Dabi's hand tight]
Dabi: Kurogiri can you take me to base
Kurogiri: Okay
Few minutes later
Dabi: [walking through the portal]
Toga: Dabi's- [sees the kid] who's that?
Dabi: your problem now [gives toga the kid before waking away]
Kurogiri: Dabi...why do you have a child
Toga: Is this yours and Hawksie's secret love child?
Dabi: what! No.
Toga: he looks like a mini Hawksie
Dabi: me and the bird aren't dating
Mr. Compress: Hawks and I not me and Hawks
Dabi: ...whatever
Shigaraki: Dabi, why is there a child in my base?
Dabi: none of your business, crusty
Shigaraki: the kid better not mess with my games, you reject gucci bag
Dabi: got it, handy mandy
Shigaraki: ...you need to stop handing out with Hawks
Dabi: [rolling his eyes] whatever boss [goes to his room]
Keigo: w-where is Dabi going
Toga: Don't worry about that grump
Keigo: o-okay
Toga: How about I show you something
Keigo: ???
10 minutes later
Dabi: [walks in] what is with the noise- [sees Keigo screaming and crying] oh
Keigo: [screaming, crying, wanting Dabi]
Shigaraki: DABI!!!
Dabi: what?
Shigaraki: make him stop
Dabi: what happened
Keigo: [hearing Dabi's voice, his screaming slowly stops, his crying becoming sniffles] D-dabi
Dabi: hey keigo. What's wrong? [crouching down near Keigo]
Keigo: S-she tried-
Dabi: She? You mean Toga?
Keigo: [nods]
Dabi: what did she tried to do?
Keigo: t-tried to t-teach me h-how to kill...t-tried to give m-me knife.
Dabi: ...shhh, it's okay [hugging Keigo]
Keigo: [chirps softly]
Dabi: [hums a lullaby that would come his younger siblings]
Keigo: [slowly closed his eyes, falling asleep]
Dabi: [looking at Toga] what the hell is wrong with you?
Toga: what? Knives are cool. I was teaching him survival skills.
Dabi: Toga, he's like 5. He shouldn't be seeing blood or knowing how to kill someone. He's gonna get traumatized.
Toga: ...
Dabi: what?
Toga: [grinning] you're going all mama bear because of the child
Dabi: I am not
Toga: then why are scolding me?
Dabi: ...don't read into things that aren't there.
Toga: Whatever you say Dabi-chan
Dabi: [carries Keigo to his room]
With hawks
Hawks: have you found him yet?
Tokoyami: He isn't anywhere. No one saw him leave.
Hawks: ...Tokoyami you should head home
Tokoyami: But-
Hawks: I'll will be fine. Now off you go
Tokoyami: ....okay
Hawks: [waves goodbye to Tokoyami as he walks towards UA]
An hour later
Hawks: where could he be? I checked everywhere.
Hawks: There only one thing left to do...but do I really want to risk it.
Hawks: [takes out his phone and calls Dabi]
Dabi's voicemail: [ringing, ringing] I'm sorry the number you have dial is not in service at this time, Fuck you
Hawks 💭: That little-
Hawks: [eye twitching] I'll try again
The same thing happened.
5 tries later
On Hawks's phone:
Dabi
answer your fucking phone
I don't have time for this
Answer damnit
With Dabi
Keigo: ??? [hearing the ringing] w-what's this
Dabi: my phone
Keigo: o-oh
Dabi: why don't you play with this [gives keigo an old gameboy]
Keigo: okay [starts playing]
Dabi: [gets up]
Keigo: where are you going?
Dabi: just going to be outside [gestures to the window that's connected to a small balcony]
Keigo: don't leave, please
Dabi: I'll be close by
Keigo: ...okay
With hawks
Hawks: [calling Dabi again] that motherfucker better-
Dabi: [picks up] hello
Hawks: finally!!!
Dabi: what do you want?
Hawks: meet me up at the usual place now
Dabi: can't
Hawks: what do you mean you can't
Dabi: I'm busy
Hawks: with what?!?!
Dabi: none of your business
Hawks: you don't have a job beside making my life difficult with all the arson you do
Dabi: damn what got you so snappy
Hawks: just come already
Dabi: sorry I'm preoccupied
Hawks: with what?!?!
Dabi: stuff
Hawks: I swear Dabi I will make wish you didn't push me
Dabi: ...fine, give me ten minutes
Hawks: good [hangs up]
With dabi
Dabi: hey kei, I need to go somewhere
Keigo: no
Dabi: kid, I-
Keigo: you said you'll stay with me.
Dabi: I'll be quick
Keigo: ...can I come with you?
Dabi: I don't think-
Keigo: please 🥺
Dabi: I-...no
Keigo: I promise not to get in the way [clinging onto dabi's leg]
Dabi: ...fine but you have to listen to me okay?
Keigo: okay
10 minutes later
Hawks: you're late
Dabi: I'm here aren't I?
Hawks: Anyways, I need your help
Dabi: what could the #2 hero possibly need from me?
Hawks: I don't need your sarcasm right now
Dabi: [shrugs]
Hawks: I need help finding a child.
Dabi: why ask me? Don't you have other heroes, the police, and commission to help?
Hawks: rather not have others know.
Dabi: [squints at hawks] ...you lost the child didn't you
Hawks: [his feathers puffed up] I didn't lose him
Dabi: sure you didn't. Who left you with a child?
Hawks: first off, rude. second off, I was [mutters something] so I need your help
Dabi: what was that?
Hawks: I was hit with a quirk okay. My younger self from the past appeared.
Dabi: ...
Hawks: Dabi?
Dabi: kid, you can come out
Keigo: ...[won't come out because he wants dabi to call him by the nickname he gave him]
Hawks: who are you talking to?
Dabi: kid?
Keigo: ...
Dabi: keigo-
Hawks: how do you know that name
Keigo: ...
Dabi: [sighs] kei, come out please
Keigo: 😊 [comes out, grabbing dabi's hand]
Hawks: !?!?! How?!
Dabi: [shrugs, turns to keigo] why don't you go with him? [gestures to hawks]
Keigo: no, I wanna stay with you
Hawks: he's not safe, very dangerous
Dabi: wow rude
Hawks: not helping
Keigo: no he's not
Dabi: kei, you should go with him
Keigo: no [clinging to dabi] you said you wouldn't leave me [looks like he's about to cry]
Hawks: [doesn't do well with crying children] he can come to
Dabi: I never agree-
Keigo: really? [looks hopeful]
Hawks: yup
Dabi: I-...fine