Originally posted by carthage
Warmup: Erik Selvig with an Asgardian blade
Superman gets stomped.
Round 1: Hulkbuster, IW Warmachine, Juggernaut, Riot
A bunch of characters slower, frailer, and weaker than him. Stomps.
Round 2: Vision, Scarlet Witch, Cull Obsidian, Ghost Rider
Stomps I think, though I don't know much about Ghost Rider.
Round 3: Bleeding Edge Iron Man, Hulk, Doctor Strange
The only real threat is Doctor Strange if Clark doesn't take him out of the threat immediately, but he easily could do so, and he'd one-shot him.
Round 4: Kurse, Magneto, Professor Xavier (morals off)
A bloodlusted Xavier could easily take Clark out by feats. If Superman were similarly bloodlusted he would roll through them, but morals are on, and while Clark has no compunctions about taking enemies out quickly as seen with the terrorist at the start of BvS, he might hesitate against a cripple. He is fast enough to KO Xavier before X can process a thought assuming Xavier doesn't have superhuman thought speed like in the comics (not sure if film version ever demonstrated anything of the sort). I can totally see why people would say he stops here.
Round 5: Hela, Thor (Stormbreaker), Apocalypse
Hela is frankly a non-factor. My knowledge on Apoc is a little incomplete, but he was getting worked by Quicksilver who is similarly beyond Apoc's speed, only Clark hits much harder and is not so frail. The little trick he did with the tendril wouldn't affect Clark at all.
Which brings us to Thor. Sorry friends, but Superman is so fast Thor and friends will be a statue. Would a Stormbreaker throw like the one at the end of IW be capable of killing Superman? Sure, absolutely. Will it ever connect? Not in a million years. And given Superman's feats like easily withstanding pressure that was displacing millions of tons of water, punching through the World Engine, and withstanding and separating the planet-terraforming Motherboxes, a super speed beatdown will take Thor down.
Round 6: Phoenix (Composite), Legion (Season 2), Shadow King
I know pretty much nothing about Legion or Shadow King so I can't comment on the round as a whole. Phoenix would get her daylights punched out though.
Boss: Silver Surfer
Silver Surfer stomps. He might honestly be the most powerful film incarnation of a comic character, barring maybe Reeves Superman. He could kill everyone in this thread with a single attack at the same time.