If deku had Insomniacs venom symbiote

Ascension

It was night time.Shigaraki asks toga and Kurogiri to follow him to a random building.They see a short fat man with goggles awaiting them.

Garaki:Well well,hello there children.
Toga:Who's this?
Shigaraki:A doctor,apparently he worked with all for one.
Kurogiri:Something about him seems...familiar.
Garaki:I have to say boy,I'm disappointed. Where is your team?Your power is pitiful, maybe this was a waste of time.
Shigaraki:I came here because when you contacted me to come here,you said you'd give me power.And I DO have a team,I just need to get them all in one spot.
Garaki:Very well then.
The doctor pulls a green syringe out of his pocket.
Garaki:Give me your arm.
Shigaraki sticks his arm out,the doctor injects the serum into the man's arm as shigaraki falls to his knees and lets out a scream.
Kurogiri:What did you do to him?!
Garaki:I gave him a quirk.
Toga:Huh?So he has 2 quirks.
Garaki:For now.It's a "temporary quirk".Given enough time,the quirk itself will disappear and it'll be like I never injected him with it.
Shigaraki continues to scream as green scales manifest over his skin.His hands turn to claws, his senses are growing sharper,he feels as if he's growing something out of his behind.His clothes rip and tear,unable to fit his growing body.A green scales tail emerges as shigaraki jumps at the wall.He then starts to climb to the top of the building and is soon out of site before the full results are seen,leaving his top clothing behind.
Toga:Where's he going?
Garaki:From what I understand,to get your "team" together.
At the Tartarus prison,a guard was doing his patrol when the wall next to him collapsed and a large odd shaped being emerged from the dust
Guard:W-w-what the hell are you?!

The reptilian beast roars and blitzes the guard as when he claws at the guard,his body turn to dust.The beast searches around for some sort of "control room" and eventually finds it.He kills the guard and unlocks rooms specifically for his teammates.Dabi,spinner,magne,twice, and Mr.compression.
The villains step out,curious why only their cells have been opened.The beast lands in front of them before it speaks.
???:Ffoolllowww...mmeee
The villains follow lizard out the prison and see the body's on the way out.
Dabi(thinking):Wait a second,these guys aren't just slashed apart,they're dust.Could this guy be-?
They arrive at the place,seeing toga and Kurogiri.
Twice:I'M SO HAPPY TO SEE YOU GUYS AGAIN!Who are you guys?
The beast starts to shrink as its scales and tail decompose.Bright blue hair emerges from its head.The beast was...Shigaraki?!
Mr.Compression:I didn't know you could do that.
Garaki:He can't,it's a temporary quirk.
Magne:That's amazing!
Garaki:Any symptoms?Still any "traces" of the quirk itself?
Shigaraki:No...no.
Shigaraki feels cold as Kurogiri wraps him up in his torn clothes.
Garaki:Very well then,this is your team?I highly doubt it's enough.
Shigaraki:We just need more time...
Garaki nods his head and then leaves with doubt in his heart.
Shigaraki:Here's the plan,I don't actually care about that guy.But now that you're all here... here's the real plan,you guys are going to collect more members.
Spinner:Do we really need more members?
Shigaraki:Yes
The man's confidence was surprising to his group.
Shigaraki:Listen...you all have goals...you wanted to achieve those goals.Listen to me and trust me,then you can do and be who or whatever you want to be and do.
The group understands and leaves.Shigaraki begins to talk again,but seemingly to air.
Shigaraki:They're all gone.
Shigaraki then hears a voice in his head.
???:They have no idea about me?
Shigaraki:No,they all think you're gone.
???:Good.
Flashback
As shigaraki in his monstrous form scaled buildings,he heard a voice in his head.
???:Power isn't bad is it?
Shigaraki:What...who are you?
???:I'm your new power.Though I'm ssskmewhat different from mosst.
Shigaraki:A conscious quirk?
???:Yessss.
Back to present
Shigaraki:You said that there was something you wanted to show me.
???:Yesss...now take you "massssk" off and close your eyesss.
Shigaraki does so and then feels nauseous as memories flood his mind.What is this?!Where did these come from?!What's happening?!?!
Shigaraki feels his head splitting as he remembers words.
Shigaraki's dad:Heroes will hurt their families in order to save complete strangers!
Then,everything comes back to shigaraki...his past.He was abused by his father while no one did anything to stop it,he always had this itch when he was at home.One day,his own sister threw him under the bus for something SHE did.He then remembers when his quirk manifested.He accidentally killed his dog,then his sister,and his parents and grandparents.It was then his own father came that he embraced what he did.He killed them all...he WANTED to kill them all.He just did what he always wanted to.His "itch"...it's his killing intent.
Shigaraki:I remember now.
Parts of shigaraki's body manifest scales as his muscles start to enlarge.
???:My name...
Shigaraki holds his father's hand in his own and decays it,crushing it to pieces.

Tenko:Is Tenko Shimura!!!
The night ends as Izuku wakes up in his new dorm.Izuku walks to the living room and sees everyone in distraught.
Izuku:Guys what's wrong?
News T.V:The league of villains have escaped.
Izuku gasps in horror at the news.He can't believe it.They're out?They're all out?!No...no