Earth-101

Earth-101 is an alternate reality within the Marvel multiverse in which the Avengers witness a horrific future where Thanos possesses the Infinity Gauntlet and rules over the entire galaxy, but worse yet, the planet Earth has been destroyed. Still possessing a fighting chance in the present, the Avengers must work together with any other heroes they can find to change the future.

Prophecies of the Future
The Prophecies of the Future are the events discovered by Thor during his brief stay in the future. It is theorized that if enough of the events can be changed, the horrific future will not come to pass.
 * Ultron Betrays the Avengers
 * In the future, it is revealed that Ultron, the Avengers' AI robot designed for peace on Earth overrides his programming and attempts to wipe out all of humanity. Getting ahead of the curve on this one, the Avengers dismantle Ultron completely before he has the chance to betray him. But this only sped up his inevitable betrayal, as he is able to download his consciousness into the internet and begin amassing power before he is disabled.
 * Stark Industries Goes Bankrupt, Bought Out by Oscorp
 *  To Be Revealed...
 * The Power Stone is Misused by AIM and Destroys a Small Town in Nevada
 * To Be Revealed...
 * The United States of America and Latveria Declare War Against Each Other
 * To Be Revealed...
 * The Death of Spider-Man
 * To Be Revealed...
 * Atlantis Joins the United Nations
 * To Be Revealed...
 * Hulk Goes on a Rampage in Asia, Accidentally Kills 9 Civilians
 * To Be Revealed...
 * Wakanda Recovers the Power Stone, Is Besieged by the Black Order
 * To Be Revealed...
 * The Sentinel Program is Reinstated Following Magneto's Expansion of Genosha
 * To Be Revealed...
 * Hydra Perfects the Super-Soldier Serum, Begins Amassing Army
 * To Be Revealed...
 * Galactus Devours Skrullos, Resulting in a Secret Invasion of Earth
 * To Be Revealed...
 * The Venom Symbiote Bonds to Cull Obsidian
 * To Be Revealed...
 * The Kree Empire Authorizes the Termination of All Inhumans
 * To Be Revealed...
 * The Invisible Woman Dies in Childbirth
 * To Be Revealed...
 * Asgard Closes Off Communication with the Nine Realms
 * To Be Revealed...
 * Human Torch Barricades Himself in the Negative Zone to Stop Annihilus from Invading
 * To Be Revealed...
 * Jean Grey Comes Into Possession of the Mind Stone, Unleashing the Phoenix Force
 * To Be Revealed...
 * Thanos Sacrifices Gamora, Obtaining the Soul Stone
 * To Be Revealed...
 * Doctor Strange Disappears, Leaves the Time Stone Unprotected
 * To Be Revealed...
 * Thanos Obtains the Infinity Gauntlet, Destroys Planet Earth, Conquering the Galaxy
 * To Be Revealed...

Avengers

 * Steve Rogers / Captain America
 * Tony Stark / Iron Man
 * Thor Odinson
 * Carol Danvers / Captain Marvel
 * Bruce Banner / Hulk
 * Natasha Romanoff / Black Widow
 * Clint Barton / Hawkeye
 * T'Challa / Black Panther
 * Janet van Dyne / Wasp
 * Scott Lang / Ant-Man
 * Sam Thomas / Falcon
 * James Rhodes / War Machine
 * Pietro Maximoff / Quicksilver
 * Wanda Maximoff / Scarlet Witch
 * Delaney Schafer / Roxette
 * Vision
 * Jennifer Walters
 * Vicki Potts

Fantastic Four

 * Reed Richards / Mister Fantastic
 * Susan Storm-Richards / Invisible Woman
 * Johnny Storm / Human Torch
 * Ben Grimm / Thing
 * Herbie the Talking Dog

X-Force

 * Professor Charles Xavier
 * Jean Grey / Phoenix
 * Scott Summers / Cyclops
 * Alex Summers / Havok
 * James "Logan" Howlett / Wolverine
 * Hank McCoy / Beast
 * Ororo Munroe / Storm
 * Warren Worthington III / Angel
 * Bobby Drake / Iceman
 * Kitty Pryde / Shadowcat
 * Kurt Wagner / Nightcrawler
 * Marian Carlyle / Rogue
 * Remy LeBeau / Gambit
 * Piotr Rasputin / Colossus
 * Illyana Rasputin / Magik
 * Alison Blaire / Dazzler
 * Betsy Braddock / Psylocke
 * Julianne Lee / Jubilee
 * Laura Kinney / X-23
 * Gabby Kinney / Honey Badger
 * Jean-Paul Beaubier / Northstar
 * Hisako Ichiki / Armor
 * Alistair Silvercloud / Forge

S.H.I.E.L.D.

 * Director Nick Fury
 * Maria Hill
 * Phil Coulson
 * Melinda May
 * Jasper Sitwell
 * Daisy Johnson / Quake
 * Bobbi Morse / Mockingbird
 * Jessica Drew / Spider-Woman
 * Leo Fitz-Simmons
 * Jemma Fitz-Simmons
 * Abigail Brand
 * Antoine Triplett
 * Lance Hunter
 * Topher MacMillan
 * Amadeus Cho
 * Eric O'Grady

Heroes for Hire

 * Luke Cage
 * Danny Rand / Iron Fist
 * Jessica Jones
 * Felicia Hardy / Black Cat
 * Misty Knight / Bionica
 * Roberto da Costa / Sunspot
 * Sam Guthrie / Cannonball
 * Simon Williams / Wonder Man
 * Zelda Caraway
 * Gideon Murphy

Inhuman Royal Family

 * Blackagar Boltagon / Black Bolt
 * Medusalith Amaquelin / Medusa
 * Crystalia Amaquelin / Crystal
 * Triton
 * Karnak
 * The Reader
 * Dante Pertuz / Inferno
 * Emily Guerrero / Synapse
 * Ivan Guerrero / Shredded Man
 * Lockjaw
 * Maximus Boltagon / Mad Max
 * Noh-Varr / The Protector

Young Avengers

 * Riri Williams / Ironheart
 * Kate Bishop / Artemis
 * Dorrek VIII / Teddy Altman / Hulkling
 * Billy Kaplan / Wiccan
 * Tommy Shepherd / Speed
 * Cassie Lang / Giant-Girl
 * Kamala Khan / Ms. Marvel
 * Miles Morales / Black Spider
 * Jeff the Land Shark

Illuminati

 * Tony Stark / Iron Man
 * Reed Richards / Mister Fantastic
 * Charles Xavier / Professor X
 * Namor McKenzie / The Sub-Mariner
 * Blackagar Boltagon / Black Bolt
 * Doctor Stephen Strange
 * T'Challa / Black Panther

Independent Heroes

 * Peggy Carter / Captain Britain
 * Peter Parker / Spider-Man
 * Doctor Stephen Strange
 * Clea
 * Namor McKenzie / The Sub-Mariner
 * Matt Murdock / Daredevil
 * Hercules
 * Dane Whitman / Black Knight
 * Wade Wilson / Deadpool
 * Robbie Reyes / Ghost Rider
 * Eric Brooks / Blade
 * Frank Castle / Punisher
 * Marc Spector / Moon Knight
 * Shang-Chi
 * Elsa Bloodstone
 * Jack Denver / Terminator

Hydra

 * Johann Schmidt / Red Skull
 * Sinthea Schmidt / Sin
 * Ophelia Sarkissian / Madame Viper
 * Baron Helmut Zemo
 * James "Bucky" Barnes / Winter Soldier
 * Arnim Zola
 * Brock Rumlow / Crossbones
 * Eric Williams / Grim Reaper
 * Grant Ward
 * Mike Peterson / Deathlok
 * Wilson Fisk / Kingpin
 * Alistair Smythe
 * Dmitri Kravinoff / Chameleon
 * Robert "Bob" Denman, Agent of Hydra

AIM

 * George Tarleton / Scientist Supreme
 * M.O.D.O.C.
 * Monica Rappaccini
 * Aldrich Killian
 * Trevor Slattery / "Mandarin"
 * Tony Masters / Taskmaster / Super-Adaptoid
 * Elias Starr / Egghead
 * Ava Starr / Ghost
 * Bentley Whitman / Wizard
 * Marvin Flumm / Mentallo
 * Bruce Hogan / The Melter

Brotherhood of Mutants

 * Erik Lehnsherr / Magneto
 * Raven Darkholme / Mystique
 * Victor Creed / Sabretooth
 * Morty Tolensky / Toad
 * Emma Frost
 * Jonathan St. Allerdyce / Pyro
 * Fred Dukes / Blob
 * John Proudstar / Thunderbird
 * Jason Wyngarde / Mastermind
 * Neena Thurman / Domino
 * Dominic Petros / Avalanche
 * Irene Adler / Destiny
 * James Madrox / Multiple Man
 * Tabitha Smith / Bombshell
 * Shiro Yoshida / Sunfire
 * Arkady Rossovich / Omega Red
 * Kevin Lowell / Leviathan
 * Mia Warburton / Stardust
 * Oliver Martinez / Vapor Wave

Cabal

 * Doctor Victor von Doom
 * Norman Osborn / Green Goblin
 * Loki Laufeyson
 * Erik Lehnsherr / Magneto
 * Attuma
 * George Tarleton / Scientist Supreme

Sinister Six

 * Otto Octavius / Doctor Octopus
 * Max Dillon / Electro
 * Mac Gargan / Scorpion
 * Quentin Beck / Mysterio
 * William Baker / Sandman
 * Aleksei Sytsevich / Rhino

Independent Villains

 * Nathaniel Richards / Kang the Conqueror
 * Ultron
 * Eddie Brock / Venom
 * Cletus Kasady / Carnage
 * Aaron Davis / Prowler
 * Kevin Thompson / Kilgrave
 * Cain Marko / Juggernaut
 * David Cannon / Whirlwind
 * Curtis Connors / Lizard
 * Dakota Conrad / Screwball
 * Kenji Yoshida / Ryoken
 * Sergei Kravinoff / Kraven the Hunter
 * Baron Karl Mordo
 * Owen Reece / Molecule Man
 * Daimon Hellstrom
 * Gene Zhang / Mandarin
 * En Sabah Nur / Apocalypse

Independent Earthlings

 * May Parker
 * Mary Jane Watson
 * Gwen Stacy
 * George Stacy
 * Harry Osborn
 * Eugene "Flash" Thompson
 * Princess Shuri
 * Hank Pym
 * Rick Jones
 * Alyssa Moy
 * Alicia Masters
 * Senator Robert Kelly
 * Moira MacTaggart
 * President Wesley Marshall
 * Vice President Pamela Clarke

The Infinity Stones

 * Space Stone
 * Mind Stone
 * Time Stone
 * Power Stone
 * Reality Stone
 * Soul Stone

The Black Order

 * Thanos
 * Hela
 * Nebula
 * Ebony Maw
 * Corvus Glaive
 * Proxima Midnight
 * Cull Obsidian
 * The Cosmic Ghost Rider
 * Loki Laufeyson
 * Ronan the Accuser
 * Zak-Del / Wraith

Asgardians

 * Odin Borson
 * Freyja
 * Cul Borson
 * Thor Odinson
 * Loki Laufeyson
 * Brunnhilde / Valkyrie
 * Heimdall
 * Fandral
 * Hogun
 * Volstagg
 * Amora the Enchantress
 * Skurge the Executioner
 * Lady Sif

Guardians of the Galaxy

 * Peter Quill / Star-Lord
 * Gamora
 * Drax the Destroyer
 * Subject 89P13 / Rocket
 * Groot
 * Mantis
 * Kamaria / Moondragon
 * Phyla-Vell
 * Ez'me / Copycat
 * Beta Ray Bill
 * Adam Warlock

Kree Empire

 * Supreme Intelligence
 * Ronan the Accuser
 * Mar-Vell
 * Phyla-Vell
 * Noh-Varr
 * Yon-Rogg
 * Minn-Erva
 * Korath the Pursuer
 * Zak-Del
 * Noh-Varr

Skrull Empire

 * Queen Veranke
 * Dorrek VII
 * Talos
 * Kl'rt / Super-Skrull
 * Anelle
 * Titannus
 * De'Lila
 * Pitt'o Nili
 * Ez'me

Independent Players

 * Galactus
 * Norrin Radd / Silver Surfer
 * Sam Alexander / Nova
 * Annihilus
 * Dormammu
 * Uatu the Watcher
 * Taneleer Tivan / The Collector
 * En Dwi Gast / The Grandmaster
 * Va Nee Gast / Voyager
 * Malekith the Accursed
 * Vox
 * The Griever at the End of All Things
 * Eson the Searcher
 * Exitar the Executioner