Marvel
On Halloween Vision's costume looked like this Classic character.
Classic Loki
Who asked Winter Soldier if he wanted some milk!?
Alexander Pierce :)
See's everything in the Multiverse!
The Watcher
These powerful weapons of mass destruction that can only be wielded by beings of immense power are used as paper weights here (according to this guy)
Saw this "villain" three times in three different universes opposing three different characters in the What If series.
The monster with the octopus tenticles.
Said, "he's green so he could be a Loki, but doesn't seem like a Loki but then could be trying to trick us which makes him more like a Loki"
Mobius (about Alligator Loki)
Val
Destroyed his entire universe for Love
Strange Supreme
Looks like the Old Man from the Pixar cartoon movie "UP"
This being was conjured not made. An entire chapter is dedicated to it in the Darkhold. Is more powerful than the Sorcerer Supreme and does not need spells.
The Scarlet Witch.
This mastermind who is one of the most dangerous men in the world decided to let loose in a club (dancing) since he had been in jail for 5 years.
Zemo
"Who's got the figgy port?"
Wanted to take the Chaos Magic for herself
Agatha Harkness
Will be coming soon to Disney Plus (Green and Smart).
She Hulk
Like Nick Fury appears to be assembling a team of anti-heros and vigilantes.
Val
He looked like Darlene Connor from Roseann!?
Loki (in Thor Dark World)
They didn't know my name so they made one up. Made America afraid of an Orange!?
The Mandarin
The only other character who could defeat Ultron other than Vision.
Zola
In another universe this powerful god is reduced to a partying teenager scrubbing graffiti off a wall.
Is older than anything in the Sanctum's library, is not cosmic (Captain Marvel) or Scientific (Banner) to cause concern for Wong.
Whatever the Ten Rings are a beacon to.
He Who Remains was originally an Earthling who is descendant of this Fantastic Four member.
Nathanial Richards (great nephew of Reed Richards).
Said, "You named a pig after me?"
Alexi (The Red Guardian)
Was the smartest / fastest when it came to defeating Thanos with only one infinity stone!
Ultron
So far every episode has revealed a potential member of this future team.
The Young Avengers (Billy and Tommy, Eli, Kid Loki, Kate Bishop)
There are several variants of this being who is sometimes referred to as a Jerk.
Kang the Conqueror.