Could you imagine the destruction if a baby had the powers of a Saint? She would kick a hole right through in her mother's womb.

So, shutaura became the #9 saint?

The movie starts with a flashback to 3 years ago, where a certain airplane is about to crash. The passengers are shouting for god, the pilots are attempting a last struggle and a young girl is praying. The plane then crashes into Academy City, but all 88 passengers on the plane miraculously survived. However, when the cockpit was shown, there apparently was blood in it.
Back to the present, Kamijo and Index are walking around, and Index asks Kamijo what that space elevator is. Kamijo said that the elevator has always been in the story (this is the movie’s trick in trying to make itself canon), and a clip from the anime series with Kazakiri in was shown as the elevator appears in the background. Index is suddenly hungry and Kamijo reluctantly agrees to take her to eat. Then both of them saw a girl singing on the street with quite of a number of people lisenting.
The scene shifts to Misaka, Uiharu and Saten. Saten is sharing a song with Misaka. Misaka immediately realized that this is Meigo Arisa’s voice, and said that she knew her. (this should be content from the PSP game) Saten is shocked saying that Meigo is recently a popular internet figure. Shirai suddenly appears on her wheelchair after seeing Misaka and Saten being too close to each other and Shirai assaults Misaka etc. etc. etc. (you know….)
The scene shifts back to Kamijo and co. Meigo finished singing and everyone else left. Index just continued clapping like mad and Meigo went to thank her. Meigo said that she only likes singing and is talentless but Index and Kamijo just continued praising her. Meigo said that her dream is to sing in a concert. Touma went and sarcastically said that Index should work harder and both argued for a while. Suddenly, Meigo’s phone rings and happily told them both that someone invited her to sing in a concert. She also mentions that although she’s a Level 0, but her luck is constantly helping her. (compared to you know who) And to Index keeps nagging Kamijo to bring them to a restaurant to celebrate this.
Then three of them went to a restaurant, Index starts eating like mad. Meigo said that her invitation to sing in a concert is a miracle, while Kamijo said that it’s because of her own talent. Meigo then starts singing. Suddenly three loli magicians appeared, Kamijo uses his Imagine Breaker. When those three are on the verge of defeat, Stiyl appears and attacks Kamijo with killing intent, throwing blazing steel on him. Then suddenly a miracle happens and a wind blows away those burning steel and Kamijo is saved. Meigo suddenly remembers herself naked on a plane three years ago after seeing fire.
After that Shoutaura appears and starts fighting with Stiyl and is apparently on par with him. Stiyl barely escaped. Kamijo then asks Shoutaura which side is she on, she said that she is from a secret force in Academy City. Then Shoutaura contacts Ladylee and Ladylee demanded that she protect Meigo.
Meigo is then brought to Kamijo’s bed to rest, Index is playing some game. After Meigo woke up Kamijo asks about who she is. Meigo answers that she doesn’t know about magic, and doesn’t know why she is pursued. And she apparently only has memories from 3 years ago. She only knows that she like to sing. Somewhere in between it is said her ability is that she produces some luck power when she sings, which creates miracles.
The second day Kamijo went to school, and a whole bunch of characters (Fukiyose, Aogami etc.?) appear.

Kamijou vs. Shutaura
As usual, he wears down her mind with a speech
As usual, he punches her in the face but collapses from his own wounds..... every words must be like a punch like ATATATATATATATATATA repeat ten times .... Your Illusion is dead :heh::heh::heh::heh: ....

In Kamijo’s house, Index is bathing with Meigo. Meigo askes Index what’s her relationship with Kamijo. She replied with “cook and eater”, and praises that Kamijo is useful at times. Then Meigo is suddenly struck by inspiration and went to write a song naked, Index followed her, and Meigo told her that they’re gonna sing this song together. Coincidentally, Kamijo just came back from school, opened the door and….. (……)
The concert is going to be held in the space elevator. The second day Meigo is going to meet their boss, but Kamijo has lessons the next day and he thinks Index will be a nuisance, so he asked her to go with someone else.
She ended up going with Misaka, Shirai, Uiharu and Saten. Some people said that space elevator company is related to the plane crash 3 years ago. Ladylee (the boss) asks Meigo to prepare and the staffs asks Misaka, Uiharu and Saten to dance beside Meigo with some revealing costume.
Kamijo walks past seeing her sing, and wonders why biribiri is there, but thinks with her beside Meigo should be safe. Then he notices Shoutaura in the crowd and followed her. Shoutaura was attacked by some magician, cutting the power on the stage and blowing it up. Misaka protects Meigo but the crowd is in disarray. However with Meigo’s luck power no one is harmed.
Kamijo then fights with the magician, but the magician went and exploded something. Some steel block came falling and Kamijo protected Shoutaura. After the smoke dispersed, Shoutaura wakes up seeing Kamijo covered in blood, and attempted to help him. But a second later Kamijo’s injuries all disappeared. Then Shoutaura said that because of a certain incident in the past she lost her ability to listen to music. Music to her is just noise.
They walked out and saw Meigo spacing out, Kamijo went to comfort her as she thought that her miracle only brings trouble to everyone. Kamijo convinced her that isn’t the case.
Then Kamijo went to look for Kanzaki and Tsuchimikado, and found out the reason people are pursuing Meigo. The space elevator is apparently a copy of some Babylon magical ceremony, and Meigo has some similar properties to a saint. And when she sings there, some huge magic will activate possibly destroying the earth.
At night, Stiyl came back with the 3 loli magicians to pursue Meigo, drives some car with insane speed and fights with Shoutaura. Stiyl’s magic is somehow dispelled by Shoutaura and his car turns over. Then Tsukuyomi drives Kamijo to pursue them. Kamijo stops Stiyl but Meigo was taken away by Shoutaura.
Shoutaura brings Meigo to Ladylee. Ladylee said that miracle where 88 people survived is some curse and there is actually someone dead on the plane, the pilot. The pilot is apparently Shoutaura’s father. Ladylee said that incident involves her, Shoutaura went mad and shot her, Ladyless bled but didn’t die. Then Shoutaura tries to kill Meigo, then the magician that tried to kill her from before restrains her and locks her.
In the hospital, Kamijo in on the bed, Misaka and Index are standing on a side each. Tsuchimikado and Stiyl came and said Meigo is taken to the space elevator, and Ladylee is from the magic side.
Some big magic array appeared in the sky, Kamijo asks whether they intend to kill her to stop the tragedy and Tsuchimikado nodded. Kamijo suddenly stands up while bleeding saying that he wants to save Meigo. Tsuchimikado then said he thought as much and made preparations. Then they were brought to some space plane. Misaka came back after buying drinks and realized no one is there, and went mad.
Shoutaura was saved by her allies and went towards the top of the elevator. Meigo is threatened with the audience’s lives and agrees Ladylee’s demand to sing. Kamijo and Index wears space suits but the elevator is blocked by some robot which Anti-Skill can’t break through. Misaka went and attack the robot with Uiharu’s help through the phone.
On the other hand, Stiyl and the 3 loli magicians also broke through.
Shoutaura then saw Ladylee and starts firing her gun at her, but Ladylee just doesn’t die. In a flashback it shows that Ladylee is some doll that lived for 1000 years, and apparently doesn’t want to live anymore thus wanting to destroy the earth. Shoutaura then proceeds to try and kill Meigo.

Meigo is singing, then something suddenly explodes, audiences panicked and lost control. But Meigo uses her luck thing again and stopped the mess.
Kamijo is on the plane with Index, and was attacked near the elevator. Kanzaki went to fight but crashes back to earth instead. Then both of them arrived in the elevator and part ways. Kamijo chases Shoutaura while Index went to find Ladylee. Ladylee then says something about them being tools but Index ignored her and attempted to search for a counter spell.
Shoutaura attacks Meigo, the singing stops. Then Kamijo came and pushed (hugged?) her away and saved her. Shoutaura hates that miracle where only her father died, but Kamijo said that the miracle is the effort of her father etc. etc. and that killing Meigo will be wasting her father’s efforts.
Then the magic is about to come to effect, to destroy it they need to destroy the array and three other enchantments. So the three enchantments are left to Misaka, Anti-skill and Stiyl respectively.
Misaka encountered a whole crowd of robots stopping her, then a whole lot of Misaka Sisters came to rescue. Anti-Skill has some trouble on their side too, as Accelerator appeared with Last Order to help them (there’s a scene with Accelerator hugging Last Order in the air or something). Stiyl’s side proceeded well.
The elevator is gonna crumble, but Shoutaura suddenly sings and regained her memory. Three years ago she is exactly the young girl that prayed on the plane, then Meigo appeared on the plane as some form of her alter ego. Meigo also woke up and starts holding hands and singing with Shoutaura, they they merged. Then miracles keep appearing and the elevator didn’t crumble, and Index broke Ladylee’s magical array in time to save the world.
Kamijo woke up to see Shoutaura, who smiled at him, and Kamijo went unconscious again.
Then Sityl, Misaka etc. retreated.
The second day, Kamijo and Index are being all nostalgic about Meigo. Index says that Meigo is not a real existence, but Kamijo replies that she didn’t disappear when touched by his right hand, so she is a real existence etc. etc. Then Aleister appeared talking to Laura about something as the movie ends.

wait did Touma not fight in the final battle?