Suzumiya Haruhi no Index

A Haruhi Suzumiya/A Certain Magical Index crossover. Aleister Crowley learns about the existence and the power of Haruhi Suzumiya and sends Touma (as an exchange student) and several other agents to test his theories about her. Meanwhile, the SOS Brigade (sans the leader) is informed of this and tries its best to not to cause any trouble and especially to prevent Touma from touching Haruhi, while the latter tries to stalk him so she can find more about Academy City. Hilarity Ensues.

First arc ended in chapter 10, second arc ended at chapter 18. Last updated in 2013 with chapter 24 (in the third arc). Needs More Love, indeed.

Check it out at FanFiction.net.

"Saten: "So Haruhi san, tell me which side of a chocolate cornet do you eat first?""
 * Big Eater: Index, just as much in the original material if not more, at one point she eats so much free ramen she actually manages to make the stand bankrupt and it's owner cry.
 * Brick Joke: Haruhi reads a paper on stem cell research and becomes interested. Several chapters later, Heaven Canceller out of nowhere declares he will work on stem cell research, and Kyon deduces that Haruhi's power caused this.
 * Broke Episode: In chapter 13, the brigade has to work in the family restaurant they always go to so they can help Kyon
 * Erotic Dream: Kyon has one about
 * Eviler Than Thou: The segment where this fight happens was even named after this trope.
 * Fastball Special: flings Touma into the sky so he can punch a flying
 * Finger-Poke of Doom: Haruhi is able to bypass Accelerator's powers and flick him in the nose.
 * For Science!: Crowley doesn't care that negating Haruhi's power or otherwise messing with her could potentially destroy the universe, he's curious.
 * God Guise: The magicians worship Haruhi behind her back, believing her to be The One True God, except for
 * Idol Singer: Haruhi becomes the talk of Academy City after an impromptu performance. She does have the voice of God, after all.
 * Rescue Romance: When Kyon, she instantly crushes lusts after him, much to his annoyance horror.
 * Schrödinger's Cat: Thanks to Haruhi's subconscious Reality Warper powers, when asked to guess a card randomly drawn from a deck, she can guess a card that isn't in the deck and get it right. Some observers describe this as if someone did the Schrödinger's Cat experiment... and pulled a dog out of the box.
 * Shout-Out:

"Mugino: "Mugi chan she says… what am I some kind of moeblob now? My eyebrows are perfect damn it!""

"Haruhi: "You know what they say Capitalism, Ho!""

""Mind if I ask something… how did you saw all that stuff?""
 * Kyon says that Kanzaki and Nagato carved "a weird circle that looked like something out of that alchemist manga that ended recently."
 * The scene where Index was visiting Touma in the hospital while eating melon bread, and eventually offering one to Touma reminds one of a certain blazing Tsundere.
 * Surveillance as the Plot Demands: Aleister Crowley is able to see nearly anywhere, even inside Closed Space. Lampshaded by Motoharu.

"Aleister: I refuse to take morals lessons from someone that sold off his God just because he wanted to marry his sister."
 * Time Stands Still:
 * The Un-Reveal: Once the SOS Brigade realizes that Touma is not affected by Haruhi's powers, they excitedly ask him what happened in the Time Crash Three Years Ago. Touma sadly informs them about his amnesia.
 * Unwanted Harem: Touma, just like, if not more than, in the original; by now, he (of course unintentionally) charmed one-tenth of entire female population of North High.
 * Wham! Episode: Chapter 11. The SOS Brigade.
 * Wham! Line: You know the first line Haruhi spoke in the original source? She says it again...!!
 * In Chapter 18, Aleister receives a phone call:
 * What the Hell, Hero?: Tsuchimakaido receives this from nearly everyone else for telling Aleister about Haruhi in the first place just so he could have a bargaining chip to legalize marriage between Not Blood Siblings. Hell, even Aleister calls him on it.
 * What the Hell, Hero?: Tsuchimakaido receives this from nearly everyone else for telling Aleister about Haruhi in the first place just so he could have a bargaining chip to legalize marriage between Not Blood Siblings. Hell, even Aleister calls him on it.


 * Who Writes This Crap?: Haruhi asks who thought Touma and her touching each other being big deal was a good idea for a plot and says it's ridiculous,
 * Yandere: Hilariously enough, becomes one for Kyon.