Any information or terminology I'm missing or something that's incorrect (plan to add more eventually) let me know and I'll fix it eventually. :)
Cast of Evangelion 3.0
Source: http://neweva.blog103.fc2.com/blog-entry-1935.html
Nerv
Shinji Ikari - Megumi Ogata
The Third Boy. Shinji is retrieved from Eva-01 (which had been in orbit -- punishment by Seele?) to a new world on Earth where 14 years have passed. Held in confinement by Wille due to causing Near Third Impact in saving the second Rei. Is forced to wear an explosive collar which monitors his actions as punishment for the "sin" of causing Near Third Impact.
The SDAT is recovered along with Shinji from Eva-01's Entry Plug, but Rei 2 is not.
Originally the pilot of Eva-01, currently pilots Eva-13 alongside Kaworu.
Gendo Ikari - Fumihiko Tachiki
Called "King of the Lilin" by Kaworu.
Shinji's father. (Surname was always "Ikari" in this continuity.)
Commander of Nerv, which after the 14 year timeskip is seemingly a joint organization of Nerv--and Seele's members (which exist only as monoliths). Nerv's current members consist of Gendo, Fuyutsuki, "Rei Q", Shinji and Kaworu. Gendo wants to bring about the Fourth Impact for reasons unclear, but his motives appear to involve his dead wife Yui.
Kozo Fuyutsuki - Motomu Kiyokawa
Vice Commander of Nerv.
Yui was a student of his when he was a university teacher.
He explains to Shinji about the truth of Yui within Eva-01 as well as Rei's origins.
Rei Ayanami (Tentative) - Megumi Hayashibara
The First Girl. Pilots Eva-09.
Another Yui (Yui's maiden name: Ayanami) clone in the Ayanami Series. Rei Listens to Gendo's orders, but shows confusion at Shinji's denial of her being "not Ayanami" and being "not the original" (triggered by Mari's comments). The second Rei clone is apparently still trapped within Eva-01's core alongside Yui Ikari.
Kaworu Nagisa - Akira Ishida
Called "Seele's Boy" as well as "the First Angel".
Originally the pilot of Mark.06, currently pilots Eva-13 alongside Shinji. Eva-13 is also known as a "surviving Adams".
The 1st Angel is "cast down to" the 13th Angel because of Gendo's schemes. Kaworu puts Shinji's collar on himself to earn Shinji's trust, but in the final battle, due to manifesting blood type blue, the collar explodes.
Somehow lessened the destructive power of Fourth Impact by sacrificing himself.
Wille
Misato Katsuragi - Kotono Mitsuishi
Naval Captain of the AAA Wunder. Colonel.
Former Nerv Col Misato's Anti-Nerv organization Wille exists to destroy Nerv's Evas and prevent future Impact events from occurring.
Wille's members consist of Misato, Asuka, Mari, Ritsuko, the 3 "bridge bunnies" and the 5 new characters.
Asuka Langley Shikinami - Yuko Miyamura
The Second Girl. Left eye is covered by an eyepatch infused with Angel-Sealing Hex Glyphs, implying permanent change caused by exposure to the 9th angel. Pilot of Eva-02 Dash. She explains to ("stupid" and "brat") Shinji the "Curse of Eva", which has resulted in her and Mari being locked in 14-year-old bodies.
Calls Mari "kone megane" (glasses-wearing person with connections).
Initiates Beast Mode Code 777 with Eva-02. Eva-02 self destructs near the final film's battle, entry plug ejected.
Mari Illustrious Makinami - Maaya Sakamoto
Speaks English and Japanese. Enjoys singing in battles. Occasionally adds cat noises (meow) to her speech.
Pilot of Eva-08. Refers to Gendo as "Gendo-kun". A woman who appears to be Mari's mother appears with Yui Ikari in an old photo Fuyutsuki has.
Calls Asuka "Princess".
Ejects Shinji from Eva-13 at the end of the film. She and her Eva are recovered by the Wunder.
Ritsuko Akagi - Yuriko Yamaguchi
Deputy Head (executive officer) of the AAA Wunder.
Maya Ibuki - Miki Nagasawa
Maintenance Chief of the AAA Wunder.
Shigeru Aoba - Takehito Koyasu
Operator of the AAA Wunder.
Makoto Hyuga - Hiro Yuki
Operator of the AAA Wunder.
Sakura Suzuhara - Miyuki Sawashiro
Toji's little sister. Shinji's managing doctor. Second Lieutenant.
Kouji Takao - Akio Otsuka
Operator of the AAA Wunder. An old friend of Kaji's.
Sumire Nagara - Sayaka Ohara
Operator of the AAA Wunder. (The voice actress Ohara also participated in 1.0 and 2.0 as a Nerv operator.)
Hideki Tama - Anri Katsu
Operator of the AAA Wunder.
Midori Kitakami - Mariya Ise
Operator of the AAA Wunder.
Summary of Evangelion 3.0
Based on qu4d's 3.0 summary (thank you!) but tweaked to include what information we do know.
Wille retrieves Eva 01 and Shinji from space
but one of the Nemesis Series attacks.
Mari is Asuka's backup, but she's unable to provide much support.
The operation goes on...
and Asuka wins the battle.
The tesseract descends to Earth.
Shinji is extracted from Eva 01 (his synch rate is 0%), and Misato's Anti-Nerv organization Wille holds him in confinement for causing Near Third Impact. Shinji is fitted with a DSS Choker to prevent him from starting anymore Impacts.
Asuka mentions that 14 years have passed. Shinji and his SDAT were the only things retrieved from Eva-01. Another one of the Nemesis Series attacks the AAA Wunder, Wille's ship.
After the battle, a "new" Rei in Mark.09 is sent to retrieve Shinji.
Gendo needs Shinji for his own plans.
Mari tries to stop Mark.09 but she doesn't succeed.
Act 4
Rei wakes Shinji at the ruined Nerv HQ...
and Shinji realizes this isn't the Rei he saved but another one.
He eventually talks with Fuyutsuki who explains Yui's direct entry into Eva-01, and how the Ayanami Series are cloned from Yui.
Shinji finds a kindred spirit in Kaworu. They bond over piano playing. Kaworu earns Shinji's trust by wearing the DSS Choker.
Kaworu eventually explains to Shinji that they can restore the world. They head down to Central Dogma in Evangelion 13.
But Asuka and Mari arrive to prevent them from causing Fourth Impact.
Shinji and Kaworu--along with Rei in Mark.09--battle against Mari in Eva-08, Asuka in Eva-02.
Kaworu realizes he was tricked by Gendo/Seele. Both Spears within Central Dogma are Longinus type instead of one Longinus type and one Cassius type.
Shinji refuses to listen, desperate to reset the world to normal. Fourth Impact is initiated.
Asuka switches to Beast Mode to stop Mark.09 from hijacking the Wunder, and ends up sacrificing her unit to defeat the Eva. In Eva-08, Mari ejects Shinji from Eva-13, which seems to put an end to Fourth Impact.
Kaworu as the 1st Angel degenerates into the 13th according to Gendo's plans. Kaworu dies, but manages to lessen the effects of Fourth Impact.
Humanity almost nearly wiped out, a devastated Shinji walks the red Earth alongside Asuka and Rei.