Disclaimer:

Sonic the Hedgehog is owned by Sega and Splatoon belongs to Nintendo. I'm still learning how to make Disclaimers so don't critize me for it. This is my first crossover, BESIDES Subject 9 X Prodigal Angel, just so you'll know.

Chapter 1 - A Chaotic Mistake

"Come on, Egghead! Is that all you got?" Sonic cheerfully yelled at the evil genius, Dr. Ivo Robotnik or as most individuals would call him, Eggman. "It is IF YOU WOULD JUST STAND STILL FOR ONCE YOU LITTLE PEST!" Eggman roared in anger at the blue hedgehog. Sonic and Eggman were at Angel Island, previously known as Floating Island, fighting for the Master Emerald. Eggman was on his modified version of the Egg Dragoon, firing fire beams at Sonic, who was dodging every beam that was fired at him. Sonic yelled out "You're still missing!"

"And you're STILL annoying!" Eggman responded,

If I don't eliminate Sonic once and for all, I'm going to be listening to his insults forever! The evil genius thought with agony. Eggman continued to shoot out beams of fire from the Egg Dragoon's arm cannon but sadly, Sonic could still dodge the attack. "Doctor, we got the Master Emerald and the Chaos Emeralds." Orbot, a robot created by Eggman, said on a communication device "Excellent, did you get out of there without getting seen?" Eggman said on the device,

"About that...we sort of have trouble coming after Cubot and I."

"What kind of trouble?" Eggman said in total confusion.

A male voice was heard in the device yelling out, "COME BACK HERE YOU EMERALD THEIVES!" In a matter of seconds Eggman recognized the voice of the Guardian of Master Emerald, Knuckles the Echidna. "Oh...THAT trouble...he's not alone is he?"

"No he's not, I think it is a good time to test the new modification you made for the Egg Dragoon"

"I guess you're correct. Just get in range so we can escape. Well Sonic, I guess I'll be going now" Eggman said to his nemisis, then pressed a button and activated a device installed within the Egg Dragoon Sonic gave Eggman a confused look, because the Eggman he knew would not stop fighting until Sonic was dead.

"What are you planning Egghead?" Sonic said to his archenemy, "Oh nothing, just a Multi-Dimensional modification I created for the Egg Dragoon so it can let me travel into any dimension I want to go." Eggman lied.

"A machine that lets you go to different dimensions, typical" Sonic said with an uninterested look.

"SONIC!" Several voices yelled out the blue hedgehog's name. Sonic turned to the direction from which the voices came from and saw Knuckles, Amy, Tails, Shadow, Silver, Blaze, and Sally chasing after Cubot and Orbot, who have the Master Emerald and the Chaos Emeralds in their possession. Sonic took in a battle stance but felt something hard hit him behind his head. Eggman laughed at the fallen hedgehog because of his distraction. "Why...did I...do that?" Sonic said in pure pain before falling unconscious.

KABOOM!

"That didn't sound good" Eggman said after hearing the sound of the Egg Dragoon. At an instant second, a portal appeared behind the Dragon-like mech and began to pull it inside. Eggman began to panic and tried to pull the mech away from the portal but the force of the portal was to strong and it pulled the Egg Dragoon right in, alongside with Sonic and everyone else in it, including the Emeralds, both Master and Chaos.

(Octo Valley)

Sonic woke up and he saw mountain ranges, octopus-shaped rocks, and oddly enough, floating structures. "Why does this remind me of the Sky Sanctuary back at Angel Island? Wait a sec! Where is everyone?" Sonic said and started to look for any signs of his friends, but he could not find any of them. "Maybe I should probably search for them but why do I have a bad feeling that I am being watched?" Sonic said before running on a path. Little did he know that he was right about being watched, on a different structure, a humanoid female with octopus-like red hair was watching Sonic the whole time he was there. After he left, the female made a evil grin and transformed into a small octopus and followed Sonic.

(The other side of Octo Valley)

Tails was flying around the area trying to find anyone for the past hour. "Geez, the longer I use my tails to fly the more tired I get. Maybe a short break would be fine." Tails said and landed on a nearby structure, he looked around while resting and saw three figures on a different structure at a small distance. The figures were tentacle-like creatures with green eyes, purple-lipped mouths, and very small legs, all three of them were on small hovercrafts. Tails began to walk do a path that lead straight to them, "Hey," Tails said to the creatures, the tenticle creatures turned to Tails, looking at him with their green eyes, "uh, do you know where the nearest city is at? I'm kind of lost." Tails continued, the creatures began to look at each other, then back to Tails and gave him a response.

CLICK! CLICK! CLICK!

"What was that noise your hovercrafts were making?" Tails said in a confused tone, the creatures shot out purple blobs out of their hovercrafts at Tails, but Tails managed to dodge the incoming blobs just in time. "Woah! Was there something I said?" panicked Tails, the creatures continued to fire at Tails with no success on hitting him. One of the creatures managed to score a hit on Tail's back, covering his two tails with the purple ink. Tails fell down to the floor and saw the creatures getting closer and closer and were ready to shoot the final shots. Suddenly, a fast blur of blue came out of nowhere an used homing attack on the three creatures, knocking them out of their hovercrafts and onto the floor, struggling to stand up. "Yo Tails! What's up?" Sonic said to Tails and saw his tails were covered in ink, "I guess it's not going so well. So, who are your new friends?" Sonic continued, pointing his thumb to the creatures.

"I don't know, the only thing I did was asked them for directions and then they just attacked me." Tails replied.

"Guess they don't know how to make first impressions then." Sonic laughed.

Tails smiled and looked behind Sonic and yelled, "SONIC! BEHIND-" before Tails could finish, he got hit by a blob of purple ink. Sonic quickly looked behind him and saw a barrel pointing straight to his face and heard a feminine giggle.