Cloud Strife
Role in FFVII: Main Character [Playable]
Role in Movie: Main Character
Cloud makes a return as the main character in the movie. He is all alone in the world, wondering if they done the right thing in attempting to save the planet. He now sports a new look wearing a black outfit instead of the purple from FFVII. He carries his trademark buster sword.
Sephiroth
Role in FFVII: Main Character [Non-playable
, enemy]
Role in Movie: Unknown
Although it is currently unknown as to what role Sephiroth will play in the movie, it is now likely that he will appear as more than just a flashback. We come to this conclusion as Square-Enix has listed him under the characters section of the official site.
Kadaj
Role in FFVII: Not in game
Role in Movie: Main character [Enemy], Leader of Silver Haired Men
One of the three Silver Haired Men [SHM]. He is in opposition to Cloud and appears to be the leader of the group. Nomura has said that the story will begin to revolve around the SHM. It has been noted that he bares a striking resemblance to Sephiroth. He uses a weapon which has been confirmed as being a refined double sword and has exceptional sword
Loz
Role in FFVII: Not in game
Role in movie: Main Character (Enemy)
One of the three SHM, although the oldest of the group, he is a crybaby. His combat skills have been noted for his fight in the trailer with Cloud, and he has an extremely fast attack. He uses a weapon called "Dual Hound" which is both a shield and a gun.
Yazoo
Role in FFVII: Not in game
Role in movie: Main Character (Enemy)
Another of the SHM, however, as with all of them, little is known about what role he will play in the movie. His weapon appears to be a kind of gunblade, and is most likely the weapon confirmed to have the name "Velvet Nightmare".
Barret Wallace
Role in FFVII: Playable Character
Role in Movie: Unknown
Leaving Marlene in Tifa's care, Barret is searching for a new energy to replace Mako. It has been confirmed that the function of his right arm has changed. Only one small scene showing him has been shown so far.
Tifa Lockheart
Role in FFVII: Playable Character
Role in Movie: Unknown
Tifa made her first appearance in Jump magazine fighting Loz. Her wardrobe has been updated with her appearing to wear something similar to Rinoa in FFVIII. She now looks after Marlene and other orphans while working at Seventh Heaven.
Vincent Valentine
Role in FFVII: Playable Character [hidden]
Role in Movie: Unknown
Vincent has been living in solitary, studying the world and knows something of the current events that are taking place. Trailers appear to have made references to "Jenova" in relation to him.
Reno
Role in FFVII: Non-Playable Character [enemy]
Role in Movie: Unknown
It is unknown if Reno is still working for ShinRa, or working independently with Rude. Recent images show him fighting Yazoo, and he is shown talking with Cloud, which seems to indicate opposition to the SHM.
Rude
Role in FFVII: Non-Playable Character [enemy]
Role in Movie: Unknown
Rude made first his appearance with Reno in the April Jump magazine. More recent images show him fighting Loz and with Reno, talking with Cloud.
Marlene
Role in FFVII: Daughter of Dyne, Adopted by Barret
Role in Movie: Unknown
Marlene's role in the movie is currently unknown, although Tetsuya Nomura hinted that she and her "friends" would play an important role.
Aerith
Role in FFVII: Playable Character
Role in Movie: Unknown
Aerith has been shown as part of a flashback scene showing Cloud lowering her into the lake after her death. Recently, new images have been released of her, which only causes more speculation of her role.
Denzel
Role in FFVII: Not in Game
Role in Movie: Unknown
Denzel appears to be one of the orphans who lives with Tifa. Whether he is related in any way to Marlene or the "children" theme of the movie is not known.
Cid
Role in FFVII: Playable Character
Role in Movie: Unknown
Only one image has been released of Cid so far, with no information. He is shown holding his trademark spear weapon, which assumes he may take part in a battle or be heading towards one.
Red XIII
Role in FFVII: Playable Character
Role in Movie: Unknown
Like Cid, only one image has been released of Red XIII and no information. Therefore his role in Advent Children is of course unknown at this time.
Wheelchair Person (?)
Role in FFVII: Not in Game (?)
Role in Movie: Unknown
Kadaj is shown bowing down to a person in a wheelchair. He is covered completely in a white sheet or robe and only his hand can be seen. This is likely a man, due to the size of the hand that is shown. Possibly this could in fact be Sephiroth himself.
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So far about characters and weapons...
Note Yuffies appearance in new scans...
Source - AdventChildren.net
characters