Ultimate Chainsaw

Arrival in Tokyo

"She's here."

She killed everyone I cared about...her hypnotizing golden eyes have deceived me.

She pitted my own friends against me.

His emerald eyes met her golden ones, she showed him a dark twisted smile.

She made a finger gun and said:"Chainsaw."

As if on command an armored creature with chainsaws sticking out of its hands and head. The creature jumped to attack the Omnitrix wielder, but he was quicker and in an green light, he was replaced by ghe humanoid brown dinosaur Humungousaur.

"HUMUNGOUSAR! RAAAAAHHH!" he announced before jumping to attack the chainsaw humanoid head on.

The two warriors prepared to clash.

Everything fades to black as the roaring sound of an chainsaw is heard...

...Ben 10 is dead.

A/N: Hello there and welcome to my newest Fanfiction! This time is a crossover between Ben 10 and Chainsaw Man I call "Ultimate Chainsaw" !

There are a few things you have to know about this story:

1. This story takes place two years after the events of Omniverse, and as thus Ben is 18-years old and has the Master Control and Evolutionary Function.

2. The Devil Hunters, fiends and devils are aware of Ben's escapades and especially his defeat of Dagon.

3. The Omnitrix has reboot transformations in the database.

4. Ben's personality will be a mix between his more mature Ultimate Alien Force version and his more childish Omniverse version.

As always, I don't own Ben 10 or Chainsaw Man, they are owned by Man of Action Cartoon Network and Tatsuki Fujimoto, MAPPA Shonen Jump respectively. I just own this fic.

Warning: This fic is rated M for violence, sexual content, body horror and some stuff involving murder, manipulation and depression.

This fic contains spoilers for the entirety of the Chainsaw Man Part 1. If you haven't read the manga fully or you are an anime-only fan...I'd suggest reading the manga or follow this fic until the anime finishes airing. If you don't care for spoilers and just want to enjoy the fic...go ahead, I don't prohibit you from doing so. You've been warned

Without further wait, plese read this chaoter and enjoy! :)

Present Time.

Ben was at the time in The Plumbers Headquarters, his eyes fixated on the monitor showing an email sent by the Japanese Government for him especially.

"So the japanese government wants me to be part of the Public Safety Sector Devil Hunters of Tokyo? Why? " Ben asked Grandpa Max in confusion.

"They said they'll need someone like you on their team, with you defeating Dagon two years ago." Max answered his grandson as he was copying the paper on a d

"And why should I accept? Devil hunting isn't really part of my expertise." Ben replied as he was fidgeting with his jacket.

"Well, this is your chance to help people, you yourself told me the other day that you are bored with nothing happening in Bellwood. And, you will be able to help people again."

"I guess if it involves saving people I'll go. This hero needs some action again! Goodbye Grandpa Max!" Ben waved as he prepared to leave.

"Ben, don't forget to call me after today! And you sure you don't want some Squid Stew garnished with bugs and shrimps?" Max asked ss whatever was in the boiling pot grabbed Max with an tentacle. Max took out a pan from the drawers and started hitting the tentacle.