You vote for the one who you like more, not who's the strongest one in a fight and have fun:
Sif vs. Erik the Red (Davan Shakari)
Hulkling vs. Selene
Shaman vs. Dormammu
The Beetle (Janice Lincoln) vs. Ms. Marvel (Kamala Khan)
Cassandra Lang vs. Harry Leland
Hogun the Grim vs. Lady Deathstrike
Quasar (Wendell Vaughn) vs. Taserface
Moondragon vs. The Collector
The Leader vs. Shatterstar
Boom-Boom vs. Terrax the Tamer
Deathlok (Henry Hayes) vs. Arnim Zola
Thanos vs. Molly Hayes
Speed vs. Mastermind (Jason Wyngarde)
Talisman (Elizabeth Twoyoungmen) vs. Shadow King
The High Evolutionary vs. Meggan Braddock
Dr. Voodoo vs. Klaw
Drax the Destroyer vs. Ulik
The Super-Skrull vs. Rictor
Jocasta vs. Skullbuster I
Ant-Man (Scott Lang) vs. The White Rabbit
Baron Mordo vs. Spider-Man (Miles Morales)
Kraven the Hunter (Sergei Kravinoff) vs. Triton
Beta Ray Bill vs. Mikhail Rasputin
Typhoid Mary vs. Raza Longknife
Karma vs. Sandman
Cecilia Reyes vs. Ronan the Accuser
Morgan le Fay vs. Corsair
Hawkeye (Kate Bishop) vs. Donald Pierce
Sunspot vs. The Wizard
Madame Masque vs. Ch'od
Mantis vs. Ego the Living Planet
Angela vs. The Impossible Man
Apocalypse vs. Karnak
Rhino (Aleksei Sytsevich) vs. Sam Wilson
Patriot (Eli Bradley) vs. Sebastian Shaw
Annihilus vs. Victor Mancha
Scorpion (Mac Gargan) vs. Gorgon (Inhuman)
Chamber (Jonothon Starsmore) vs. Thundra
The Porcupine (Roger Gocking) vs. Ka-Zar (Kevin Plunder)
War Machine (James Rhodes) vs. Bonebreaker
Namorita vs. Sin
Arkon vs. Longshot
Fandral the Dashing vs. Pretty Boy
Taskmaster vs. Karolina Dean
Crimson Dynamo (Dmitri Bukharin) vs. Darkstar (Laynia Petrovina)
Julia Carpenter vs. Shriek
Graviton vs. Doc Samson
Jessica Jones vs. Malekith the Accursed
Superia vs. Genis-Vell
Emma Frost vs. The Trapster (Peter Petruski)
Tiger Shark vs. Slapstick
Mar-Vell vs. The Supreme Intelligence
Sauron vs. Firebird
Ultron vs. Nico Minoru
Viper (Ophelia Sarkissian) vs. The Punisher (Frank Castle)
Clea vs. Umar
Constrictor vs. Feral
Sunfire vs. Baron Zemo (Helmut)
Skurge the Executioner vs. Thunderbird (John Proudstar)
Warpath (James Proudstar) vs. The Abomination
Witchfire vs. Machine Man
Songbird vs. The Hypno-Hustler
Blastaar vs. Chase Stein
Balder the Brave vs. Omega Red (Arkady Rossovich)