We're in the middle of a renaissance for the character of Lex Luthor. Superman's arch nemesis has made a huge splash in the last two years, forming a new incarnation of the Legion Of Doom and making big moves across the DC Universe, going so far as to wake the mother of the Multiverse in an effort to restart things in an image he'd find more pleasing. He's Apex Lex in more ways than one.
With all of that said, how would Lex Luthor stack up against the heroes of the Marvel Universe? Without allies or knowing the lay of the land, who would he defeat? Who would defeat him?
10 Would Lose To: Mr. Fantastic
Reed Richards is one of the smartest men in the world. That's what going to win him this fight. While Richards' stretching powers make him very formidable, Lex could figure out a way to nullify any advantage that would give Reed and even think of a way to use that against him.
The battle between them would basically be a chess match, as each one comes up with a new advantage and the other shuts it down. While both men excel at this sort of thing, and Lex is likely to cheat, Reed is used to matching wits with Doctor Doom, a man who is arguably Reed's superior in every way. Lex, on the other hand, is only Reed's superior in ruthlessness. Reed would be able to out-think Luthor and take him down.
9 Would Defeat: Iron Man
Stark is good, but he's nowhere near Luthor's level in any way. Luthor is smarter, more devious, a better strategist, and his armor, made to allow him to go toe to toe with Superman, is way better. Stark's armor struggles against the Hulk, a guy's whose base strength is waaaay below Superman's. Even Stark's specialty "Hulkbuster" armor fails against the Hulk and it was specifically built to battle him.
Stark is outclassed in every way by Lex. It's actually doubtful he'd put up a good fight against Lex. Lex would defeat him, then take over his company, and run it better than Stark ever could, merely out of spite.
8 Would Lose To: Professor X
Lex is smarter than Professor X, but one thing that the DC Universe doesn't have is a telepath on Xavier's level. In general, the telepaths of the DC Universe can't hold a candle to any of the ones in the Marvel Universe, and Xavier is the best one of them all. Lex would have no defense against Xavier.
Xavier, however, would be able to sense Lex coming a mile away, know his intentions, and put him down before he even got close enough to do any kind of damage. There would be no fight, no matching of wits. Xavier would just switch Lex off.
7 Would Defeat: Captain America
Captain America has gone up against a lot of evil masterminds, but none of Lex's caliber. Lex's schemes and tech have to be built strong enough to deal with Superman, a being who is more powerful than most of the Marvel Universe combined. Cap is a good fighter, but his physical abilities don't hold a candle to what Lex is used to dealing with.
Lex's armor would also allow him to take the fight to Cap. Cap may be a much better fighter, but Lex's armor makes Iron Man's armor look like a child built it, and Cap had enough problems with that armor without cheating. With no S.H.I.E.L.D.-built countermeasure to fall back on, Cap loses.
6 Would Lose To: Magneto
All the smarts in the world aren't going to help Lex in this fight. Much like the battle against Xavier, Lex is just outclassed on a power level by Magneto. Magneto could stop Lex's blood flow with a thought. There's really nothing Lex could do against that.
Given enough time, Lex could definitely come up with a mutant power inhibitor, but Magneto wouldn't give him that kind of time. Unless Lex used only non-ferrous metals in his tech, Magneto can take him easily.
5 Would Defeat: Spider-Man
Spider-Man is a well-balanced foe. He's smart, strong, and fast. Unfortunately for him, he's not as smart, strong, or fast as Superman, which means Lex is ready for anything he could do. His spider-sense would give him a bit of an advantage for a time, but Lex would figure out a way to overload it or negate it.
Lex makes things more durable than Spidey could deal with, and his armor makes more than a match for the Wall-Crawler. Spidey would get some good bald jokes in... and that's it.
4 Would Lose To: Doctor Strange
Magic is something that Lex doesn't have a lot of experience with. He's always left stuff like that to other people. Lex is a rational man and magic is the height of irrationality. He respects magic users, but he believes he's better than them.
Doctor Strange would show him otherwise. He'd be able to take out any of Lex's technological creations and could nullify any advantages Lex's armor gives him. Lex wouldn't know how to deal with Strange's magic and that would be his undoing.
3 Would Defeat: The Hulk
The Hulk is a very dangerous opponent, but he also represents a threat from only one area: his strength. Lex is used to facing strong enemies who are also smart. That's not the Hulk. Hulk is like a wild animal; dangerous, but only if one isn't thinking enough to use all of the weapons at their disposal.
Lex would quickly figure out a way to drain off Hulk's gamma energy, rendering the Hulk powerless. Lex's armor would allow him to physically battle the Hulk until his tech could drain Hulk's gamma energy. Once he's powerless and back to being Banner, Lex would take him out.
2 Would Lose To: Thor
Thor has the kind of power set that Lex is used to dealing with, but he's not used to dealing with someone like Thor and that's why Thor wins the fight. First off, Thor's powers are magic-based, and that's not something that Lex is used to dealing with. Secondly, Thor's power level may be comparable or a little less than Superman's but he's a warrior born.
Lex isn't used to dealing with someone with Thor's power set and that kind of attitude. Plus, Thor is a god. Lex couldn't figure out a way to take away his powers. With no equalizer, Thor gets the win.
1 Would Defeat: The Sentry
The Sentry is the Marvel version of Superman. Being a Marvel character, he has some flaws and such, plus his dark side, the Void, is a world-ending threat. However, he's proven to be easily manipulated and not nearly as shrewd as Superman.
That will be his undoing. Lex is used to dealing with someone as powerful as the Sentry is. He can use the Sentry's precarious mental state against him and even if the Void comes out, Lex would be able to deal with it. Lex could probably even just pull a Norman Osborn on the Sentry and convince him that Lex is on his side and then take him out quietly, draining off his power and putting an end to the Golden Guardian of Good.