In a timeline which Eggman's creation Metal Sonic rebel against his creator with the help of his new master Evox as they are ready to wipe out all human and organics as Earth will be a home for the machines.

After the end of the Eggman War (the event of Sonic Forces) and Eggman mostly focus on Infinite and the Phantom Ruby, Evox (thank to Mephiles) found Metal Sonic as he upgraded him. After six months of peace, the two arrive but with an army of replica of Metal Sonic, Neo Metal Sonic, prototype Mecha Sonic (StH2 8-bit), Mecha Sonic (StH2 16-bit), Mecha Sonic mk II (S&K), Mecha Sonic mk III  (Sonic Adventure), Metal Knuckles, Mecha Knuckles, Tails Doll, E-100 Alpha/ Zero, many of the E-100 series, etc. Planet Earth was in a constant war as Evox stole technology of the Omnitrix and many morphers to copy the powers and abilities of Aliens & Rangers. Metal Overlord vow to destroy Cinos and use the Chaos Emeralds to destroy him in hope to get rid of him from Evox's plan. While Metal gather the 7 Chaos Emeralds, Evox banish most the most plumbers and various aliens to Null Void and capture various Power Rangers to drain their power. Evox and Metal bring back a project Eggman try to used but didn't have the time, creating the dangerous Metal Virus which will turn human, mobians, aliens, etc into zombots. Cinos kept one Emerald while Metal already found one but Cinos decided to used send the rest of the 5 Emeralds to random universes he never visited. Cinos travel in these 5 universes and meet new people (he also developed feeling for Mei, Daki, Sasha, Soriya, and Evil Android 21) but sadly Metal & Evox following him as they used five copy of the Annihilargh and erased these 5 universe, Cinos save most of the people he new during these adventures. Now with no home, they join the war against Metal & Evox.

This AUs is inspired by Sonic Heroes, the 1st Saga of IDW Sonic The Hedgehog, Terminator series, Powerful Rangers RPM/ Beast Morpherd, & The Metal Virus Saga, elements of Kingdom Hearts, Super Smash Bros, Marvel vs. Capcom: Infinite, Spiderman: Shattered Diemnsion, Transformers: Rise of the Dark Spark, Dragonball: History of Trunk, and Ben 10 (which involves travel to other worlds) but primarily the infamous webseries Super Mario Bros Z created by Mark Hayne a.k.a. Alvin-Earthworm. I view this AUs to be a mechanical counterpart of the Dark Gaia Kingdom AUs

Here are Sonic characters who are killed (only Sonic characters)  
Sonic The Hedgehog
Knuckles The Echidna
Espio The Chameleon
Big The Cat
Tikal
Vanilla The Rabbit
Mighty The Armadillo
Ray The Flying Squirrel
Bark The Polar Bear
Avatar
Shadow The Hedgehog
Chaos
Abraham Tower
Jet The Hawk
Storm The Albatross
Bean The Dynamite
Ivo "Eggman" Robotnik
Fang The Sniper
Eggman Nega
Imperator Ix
Zavok
Zeena
Zor
Black Doom
Infinite
Heavy The Robot
Bomb
Honey The Cat
President (From Sonic Adventures & Shadow The Hedgehog)
President Michael
Professor Pickles
King Shahryar
Chuck Thorndyke
Nelson Thorndyke
Lindsey Thorndyke
Hawk
King Boom Boo
Jerome Wiseman
Mr. Schmitz
Dark Oak
Pale Bayleaf
Black Narcissus
Yellow Zelkova
Red Pine
Starline
Rough The Skunk
Tumble The Skunk
Mimic
Clutch The Opossum
Surge The Tenrec

Here are Sonic characters who survived  (only Sonic characters)
Miles "Tails" Prower
Amy Rose
Vector The Crocodile
Charmy Bee
Cream The Rabbit
Cheese
Silver The Hedgehog
Blaze The Cat
Marine The Raccoon
Yacker
Wave The Swallow
Shade The Echidna
Merlina
Orbot
Cubot
Master Zik
Zomom
Zazz
Birdie
Maria Robotnik
Chocola
Princess Elise The 3rd
Shahra
Sinbad The Sailor
Ali Baba
Sir Lancelot
Sir Gawain
Sir Percival
Ninue
Blacksmith
Sir Galahad
Sir Lamorak
Dodon Pa
Chris Thorndyke
Helen
Danny
Frances
Ella
Mr. Tanaka
Mr. Stewart
Topaz
Sam Speed
Christina Cooper
Scarlet Garcia
Kim Bickley
Albert Butler
Cosmo
Tangle The Lemur
Whisper The Wolf
Jewel The Beetle
Kitsunami The Fennec
Nite The Owl
Don The Rooster
Lanolon
Belle The Tinkerer

On the bad side or rebuilt
E-123 Omega
E-102 Gamma
Emeral
Gemeral
SCR-HD
Metal Sonic 3
Captain Whisker
Ergo