Izuku is kind of written OOC, unless that was the intention. He has the "all powerful, arrogant prodigy a-hole" vibe going on, especially with the whole challenging Aizawa thing.

Also, even when you shift perspectives, it really doesn't seem like you did, since for one, there's no visible transition from one character's POV to the next. Bold text, italicize text, center certain text, divide the page with ellipses or the big line gives you. And also, the writing style needs to change as you shift from one person to the other.

I love your story and i would like to suggest that an Izuku/Momo or even better an Izuku/Momo/Mei pairing would fit really good in it and that you could take inspiration for it from the Iron-Man/My Hero Accademia Crossover "Building from the ground up" by " ".

Surprised there was actually a fic like this. I'm stoked to read more

Yassss! I like this! I REALLY REALLY LIKE THIS! Keep it up! Your writing is phenomenal!

I love the challenge that Aizawa has taken on for himself. Keep up the good work!

wonder if he finds a cool animal/plant with a quirk could he do a killer queen and store him in his stomach/insides to attack

Gotta say, haven’t seen a story like this before. I quite enjoy it, keep it up

Have him make a pet robot which is one of the machines from the terminator movie the big flying one I don’t know it’s name

I like how you realized how Izuku's personality would change! With the quirk he already has, and having a friend like Kaachan, would definitely make him a little more arrogant. I think you realizethe cause and effects when something changes, and you only use lines from the show when it is necessary. You also made Kaachan more carefree. Kaachan and Midoryia still have the same goals, but Izuku revealing his quirk at an early age kept those two friends. I really like how things fit in perfectly!

The only thing I would critique is to correct your typos and grammar mistakes.

This is chapter is all over the place

Deku should've knocked him out for those horrid actions.

Now another question since deku's outer shell is kinda of a sandish type of nanotech/phase matter could he use whatever tech/metal laying around to make a outer metallic/tech combat shell?

Such famous examples he could turn into if possible though maybe limited to human size only in certain ones.

1st 80's/90's Robocop?

2nd Judge Dredd movie ABC warrior?

3rd Gundam MS's?

4th Transformers prime bots/con's?

5th Zoids?

6th Iron man armors?

7th Power armors like ones from Fallout?

8th Spider Bot from the Incredibles movie?

more please OuO

"My only response to his incredulous face was my own shit eating grin. Two could play at this game." and cue the Terminator main theme! It fits the moment, so what Izuku hero costume will be? And when he will say some of the classic Terminator lines like: “Hasta la vista baby” or the iconic “I'll be back”?

Izuku you sarcastic bastard. this had me grinning from ear to ear from the start.
Nezu would probably enjoy talking with the living machine considering that they both are slightly crazy.

cant wait to see who you are going to pit him up against during the heroics class.

this is a so fucking cool story. i once start working on a fic where izuku have a t-1000 ish quirk and i say we think similar. did we just became best friend?