My Hero Academia: The Rise of Ben 10, Book 2

The Foggy World.

"WHAAAAAM!!" Izuku hurled a Full Cowling powered punch straight into Kraab's face, causing the injured mercenary to skid back on the street, sparks spitting out from the points of his crab-like legs. 

"YOU LITTLE!" Kraab hurled open his pincer, firing energy blast after energy blast at Izuku. "YOU CAN'T WIN! You're the only one left!! You couldn't even keep up with me without your friends! What hope do you have without em!?"

Izuku gritted his teeth, dashing and leaping at high speeds to avoid the deadly plasma bolts. He twirled into the air and aimed his fist as he charged unbelievable power into this arm.

"100 PERCENT TEXAS SMAAAASH!" Izuku hurled out his fist, unleashing all of One for All's power.

"KAAABOOOMMMMMMMMMM!!!" The street erupted in a huge crater as Izuku's arm turned limp and broken. 

Kraab's red eyes shone with shock as he skidded out of the way just barely.. "H-holy shit.. HOLY FUCKING SHIT!! J.. Just what.. kind of kid ARE YOU!?"

Izuku panted, landing on his feet, his arm limp at his side.

"It seems that huge power comes at a cost though." said Kraab. "Very unique! I gotta admit, it's rather incredible. HAHAHA! I love it! Guess if you're using YOUR last resort, it's only natural to use mine as a form of respect as warriors!"

"Wa-warriors?" 

"Yeah, kid I admit I'm pissed you all pushed me this far, but I'm also kind of grateful ya know!? You were some DEEPLY entertaining opponents, and that's saying quite a bunch considering you're a bunch o' humans! YEAH!!! HAHAHA!  I'll show you.. THE  BEST ME THERE IS!!"

"CLINK CHINK CHINK.. SHEEEEN!!" 

The metal on Kraab's body began to expand as multiple robotic parts erupted around his body, disassembling and reassembling at rapid speed.. 

Izuku backed away as a large shadow now loomed over him

Kraab's robot body had grown massive, his torso now covered in multiple different kinds of weaponry, from missile launchers to plasma launchers. His legs had grown too, now possessing powerful stabilizers and thick metal spikes.  

His shoulder armor was silver now, and  bulky to the point that they dwarfed his unchanged head, and his left hand possessed a plasma gun, while his right giant pincer was huge and now big enough to chomp an entire bus in half. 

"Hyper-Combat Mode engaged! HAHAHAHAHAHAHA!" Kraab laughed. "LETS DO THIS!! DEKU BOY!!!"

Kraab hurled his massive pincer down at such speed, all Izuku could do in his shock as stare the rapidly approaching death straight in the face..

"Do not fear.. we shall help.."

Suddenly, fog whirled into the scene.. and in an instant, a barrier made of what appeared to be solid clouds deflected Kraab's powerful blow. 

"The hell!?" Kraab stammered. 

In that moment, a strange fog began to fill the entire street..  everything was shrouded in mist.

"What the heck is with this planet's weather now?" growled Kraab, his head turning to and fro to look at the foggy environment.  EH!? YOU!!"

Kraab looked to see Izuku on his right, firing his weapons all at once, sending explosions raining through the area.. 

But the Izuku that he had seen had dissipated into fog.. and right after that, more Izuku's started appearing mysteriously all over the place..

"Th.. THE SHIT IS HAPPENING HERE!?" Kraab yelled.