What Really Killed Aerith?Edit
In the most infamous scene regarding the video game industry, Sephiroth murders Aerith while she was praying in the temple. Cloud later gives her a burial at sea. This theory posits that because there wasn't any blood shown during Aerith's death scene, it could logically mean that she simply passed out from shock after Sephiroth's sword severed her spinal cord, and that Cloud himself accidentally killed her by burying her at sea.
Squall is DeadEdit
In Final Fantasy VIII, Squall and company face Edea in a floating city. When it seemed as though Edea was defeated, she spitefully conjures up an ice shard that impales Squall. He then proceeds to fall off the platform. He's surprisingly healed in disc two, and there isn't even a wound to prove that he was stabbed. This led some people to think that Squall was actually dead the entire time.
Rinoa is Ultimecia Edit
A popular theory for Final Fantasy VIII is that the deuteragonist and love interest of main character Squall, Rinoa Heartilly, is actually the main villain Ultimecia. At a point in the game, Edea asks Rinoa to choose a Knight for emotional support to help deal with her power as a sorceress. Squall volunteers, which fans speculate that after the game's events, Squall dies defending Rinoa and she, mad with grief, seeks to create Time Compression to be reunited with her beloved. This idea is based on several hints within the game, such as the fact that Ultimecia’s Guardian Force bears the same name (Griever) as a ring that Squall gives to Rinoa during the course of the game. However, before fighting Griever, Ultimecia claims to attach to one of the party members (Squall). It can be assumed that, in doing so, Ultimecia’s GF or, in fact, Ultimecia herself takes a part of Squall which he holds close - the Griever emblem. As such, it should also be noted that Griever is not only part of the ring which Squall gave to Rinoa but is, also, presumably, the lion head at the end of his keychain and on part of his many belts.
It is also worth noting that both Rinoa and Ultimecia share near identical facial structures in FMV sequences (which is emphasized by the final shot of Rinoa’s face within the game, which flashes several times to Ultimecia’s). Furthermore, Rinoa and Ultimecia are the only two Sorceresses who are shown to have wings—Rinoa grows white wings for her Angel Wing Limit Break, and Ultimecia possesses black wings when you meet her at her castle. Due to the Knight references throughout the game, it can be expounded that as her friends died around her, Rinoa became dark and twisted and yet Squall kept his promise to be beside her always. As such, he became Griever.