''[[http://www.fanfiction.net/s/5984453/1/SmallvilleX_Evolution SmallvilleX: Evolution]]'' is a crossover between {{Smallville}} and XMenEvolution by ben10987654321. This story is the first part of a series that so far consists of:

* ''[[http://www.fanfiction.net/s/5984453/1/SmallvilleX_Evolution SmallvilleX: Evolution]]''
* ''[[https://www.fanfiction.net/s/7513368/1/SmallvilleX-Evolution-Year-2-1-Crusade SmallvilleX: Evolution Year 2:1: Crusade]]''
* ''[[https://www.fanfiction.net/s/9071403/1/SmallvilleX-Evolution-Year-2-2-Best-Served-Cold SmallvilleX: Evolution Year 2:2: Best Served Cold]]''
* ''[[https://www.fanfiction.net/s/10204217/1/SmallvilleX-Evolution-Year-2-3-Dark-Horizons SmallvilleX: Evolution Year 2:3: Dark Horizons]]''
* ''[[https://www.fanfiction.net/s/10540641/1/SmallvilleX-Evolution-Ascension SmallvilleX: Evolution: Ascension]]''
* ''[[https://www.fanfiction.net/s/11089769/1/SmallvilleX-Evolution-Reality-Unravelled SmallvilleX: Evolution: Reality Unravelled]]''
* ''[[https://www.fanfiction.net/s/11149133/1/SmallvilleX-Evolution-Year-3-1-Hellfire-Burns-Eternal SmallvilleX: Evolution Year 3:1: Hellfire Burns Eternal]]'' (In Progress)

and also the following 2 omake chapters:

* an outline of Earth 2 (Evil Mirror Universe): ''[[https://www.fanfiction.net/s/9843623/1/SmallvilleX-Earth-2 SmallvilleX: Earth 2]]''
* a possible glimpse of the future: ''[[https://www.fanfiction.net/s/11133319/1/SmallvilleX-Evolution-Death-Rebirth-and-Something-In-between SmallvilleX: Evolution Death, Rebirth and Something In-between]]''

So far the series has covered Seasons 2,3 and 4 of XMenEvolution, and Seasons 3, 4 and part of 5 of Smallville.

The story begins when the Kents are about to lose the farm after Clark's Red Kryptonite binge in Metropolis. Lex Luthor is out of the country and is unable to buy the farm like he did in canon. Virgil Swann informs Charles Xavier of the situation and recommends inviting Clark Kent to the institute in Bayville.

Meanwhile Magneto and Sabertooth are in Smallville investigating the Kryptonite infected mutants. While most of them are too unstable for Magneto to use he is hoping at least one of them is a genuine x-gene mutant that can fight for his cause. He receives a tip from Dr. Essex at Belle Reve to observe Clark Kent, whom Essex believes is simply an extra powerful mutant.

What's notable about this crossover is the effort made to blend the two stories together. The backstories are fused together nicely and the threats are a mix of villains from both continuities. The author isn't afraid to use characters from other Superman/X-Men continuities if it helps the story.

!!This series provides examples of:
* AccidentalPornomancer: not as dramatic as most examples, but Clark tends to attract a lot of women (though, in a number of cases, he would be very happy if they just left him alone).
* AdaptationalHeroism: Volcana is a slightly psychotic AntiHero instead of a sympathetic AntiVillain.
* AllYourPowersCombined: Clark has a version of Scott's optic blast, Juggernaut's strength and invulnerability, Pietro's speed, Logan's healing factor and enhanced sense of smell, plus super-hearing and x-ray vision. No wonder Magneto wants Clark on his side.
** In the sequel Clark also has ice-breath (somewhat similar to Bobby Drake/Iceman's power - in fact he uses it to frame Bobby for a prank), has super-breath and is starting to develop his flight power (while not able to fly properly as of the most recent chapter, he can slow himself down when falling)[[spoiler:He now has full flight after Lional Luthor tried to nuke Smallville]]
* BadassLongcoat: Clark occasionally wears one of these.
* BeamOWar: Scott's Optic Blasts vs Clark's Heat Vision. They were tied until Kryptonite was used.
* BoxingLessonsForSuperman: Clark learns how to fight, primarily from Logan.
* BreakingTheFourthWall: {{Deadpool}} of course.
* TheCameo: Spider-Man makes an appearance as well as a few members of his RoguesGallery. The author has also stated that {{Deadpool}} will appear in the future.
** The so-far incomplete sequel has [[IncredibleHulk Bruce Banner]] make an appearance.
** Stan Lee made a cameo appearance at a party of Tony Stark's in the most recent chapters, and the Fantastic Four made an appearance at that party as well.
* TheCape: Clark, naturally, though, at points, he leans more towards TheCowl.
* CharacterDevelopment: one side effect of Clark joining the Institute and no longer fixating on Lana is that he grows up one hell of a lot faster and leads to him [[spoiler: becoming Superman, albeit in the gear he was wearing in Smallville Season 10 or a BadassLongcoat, rather than the classic Cape]]. It also, however, [[spoiler: leads to him developing fully fledged Multiple Personality Disorder]].
* ClarkKenting: Obviously, but puts more effort into making it plausible than canon.
* CorruptCorporateExecutive: Lionel Luthor.
* CrossOverShip: Clark/Rogue. [[spoiler:broken up at this point, Clark/Calypso, Clark/Jean(hinted/teased), Jean/Arthur Curry]], Jubilee/[[spoiler:Bart]]
* DemotedToExtra: Lex only makes one appearance, and that's just to explain why Chloe and Pete are in New York right before Christmas. He's out of the country for most of the series.
** Lex has made more appearances since then, and has had a bigger part in things so far, though he still isn't appearing nearly as much as he does in Smallville.
* DistractedByTheSexy: Several characters experience this, particularly when Clark is shirtless.
* DontExplainTheJoke: Often the author will add asides to explain completely obvious comments, innuendo, and jokes.
* FridgeLogic: In-universe. When Magneto discovers Clark's weakness he observes that it makes no sense for an invulnerable mutant to succumb to space rocks. He knows he's missing something, but doesn't make the alien connection.
* GambitPileup: Headed this way. We've got Xavier's plans for peace, Magneto's plans for mutant domination, Lionel's plans to exploit mutants, Mystique's own agenda, Stryker's mutant vs mutant plan, Trask's Sentinel project, Apocalypse's plan to take over, and Jor-El's plan to do God knows what.
** It's getting even more complex now - Trask is in jail for the moment after the Sentinel attack that exposed mutants to the world, but with the Hellfire Club has been getting involved in recent chapters. Magneto and SHIELD are both after the Kryptonian Stones of Power, and the Hellfire Club might soon join them thanks to Isobel (the witch who possessed Lana in Smallville Season 4) joining up with them (her mother is [[spoiler:Selene, the Black Queen of the Hellfire Club]] Plus Lionel and Lex are both working with SHIELD for their own reasons, and Lex just made an alliance with a member of the Hellfire Club.
* GeniusBruiser: Clark is very adept at using his brains in combat.
* ILetGwenStacyDie: not a literal death, but [[spoiler: the fact that Lana is still being possessed by Isobel and that he failed to save her]] is something that consistently bothers Clark.
* KryptoniteIsEverywhere: Even when Clark is 1000 miles away from Smallville the GreenRocks just will not leave him alone. [[spoiler: When he learns to fly, he makes a point of finding as much as possible and throwing it towards the Sun]].
* MakeOutKids: Clark and Rogue are like this, for a while.
* MamaBear: Mystique is like this with Alicia, whom she adopted for legal reasons but, eventually, genuinely cares for. She's like this with her other children too, one way or another.
* ManipulativeBastard: Kal (Clark on Red K) arranges a fight between the X-Men and himself and the Brotherhood simply to get Rogue to absorb Alicia and find out how she knew about Red K.
** He later proves to be exceptionally good at this, to the point where [[spoiler: he plays the entire inner circle of the Hellfire Club like a violin]] and the X-Men note that a) Kal is dangerous, b) he always has his own agenda. Clark isn't half bad at it either, since [[spoiler: he let Kal out on purpose]].
* NiceGuy: Clark, most of the time.
* OccamsRazor: Lampshaded. Rogue's power doesn't work on Clark simply because he's an alien. [[spoiler: Until her powers get amped by a machine designed to mutate people with Green Kryptonite]].
* [[OhCrap Oh Crikey]]: Pyro's response to seeing Colossus beaten by Clark.
* PsychicBlockDefense: Telepaths can't understand Clark's alien thoughts [[spoiler: or more precisely, those of whoever happens to be in his body]], as if they are spoken in a foreign language.
** Magic, however, can and does override this.
* RedHerring: During the search for missing Jean some {{Smallville}} fans will notice Clark's sudden fatigue and expect him to develop super-breath like when this happened in canon. However it was just a sliver of Kryptonite doing that and no new powers in that chapter.
* TheReveal: [[spoiler: Sebastian Shaw, Martha's OldFlame, reveals that he used a lock of Martha's hair to rewrite an egg cell into becoming one of hers, fertilised it with his sperm, and had a surrogate carry the resultant child - Claire Selton a.k.a. Volcana, making Claire Clark's sister, albeit by adoption]].
* ShipperOnDeck: Kitty encourages Rogue and Clark to get together.
* SpannerInTheWorks: Clark's super-hearing lets him detect Mystique despite her enhanced shapeshifting, which prevents her from executing her plans to infiltrate the institute.
* TheSpock: Clark's Kal-El personality and, at points, Clark himself, can come off as this. [[spoiler: It's part of what causes the collapse in his relationship with Rogue]].
* VillainessesWantHeroes: Clark is, occasionally, on the receiving end of this, much to his chagrin.
* WhatHappenedToTheMouse?: Since Clark left Smallville, who's fighting the MonsterOfTheWeek?
** There's been more than one reference to a private security force led by Lex that's helping the police to keep the peace in Smallville. Presumably they're dealing with the various Monsters of the Week.
* WhatKindOfLamePowerIsHeartAnyway: Spider-Man feels his powers are this in comparison to Clark's.
-->"I need better powers."
* TheWorfEffect: Clark brings down Beast, Storm, and Logan in minutes by himself while under Red Kryptonite, just to show off how much the X-Men are screwed without Green Kryptonite.