During its original story run, Kingdom Hearts 3 introduced a brand new character to the series by the name of Yozora -- some players may not have realized it at the time, though, as his introduction was unconventional.
Yozora made his first appearance on Toy Box, the KH world based on Toy Story. He appeared in a video game commercial as the main character of a series called Verum Rex, which became a mini-game that players could experience as Sora. In this way, Yozora came off as just a costly way to introduce one of KH3's many mini-games.
However, during KH3's secret movie, Yozora made another brief appearance, confirming that he was, in fact, someone of importance. This became more evident in Re: Mind's final trailer, where Yozora appeared once again, but this time, he had a full-on face-to-face with Sora, even mimicking the main character's very first lines of dialogue in the series. Now, days before Re: Mind's release, Yozora has received one more tease in the form of tweeted screenshots taken from the DLC's final trailer. The screenshots -- along with the tweet's text -- go over Sora's Re: Mind journey to save Kairi, and his meeting with this mysterious "other person": Yozora.
As it stands now, Yozora looks to be the character who'll end up being the secret boss of Re: Mind's limit-cut episode, though that is mere speculation at this time. What he can do will more than likely be further detailed in this episode and boss battle. If Yozora does end up being the game's official secret boss, he'll definitely be explored in the series next installments, as that's what happened with Unknown, Lingering Will, and Mysterious Figure (the secret bosses of previous KH games).
Yozora's video game commercial introduction makes him one of Kingdom Hearts' biggest mysteries to date. Is he real or not? Is he just another one of Sora's strange thoughts? Nomura, Kingdom Hearts' long-standing director, gives a little more insight into the character through statements made in the Kingdom Hearts 3 Ultimania interview.
According to him, the setting of Kingdom Hearts 3's secret movie takes place in Verum Rex, and Verum Rex takes inspiration from unused Final Fantasy Versus 13 concepts, which explains why the two seem so similar in presentation. Nomura was the prime director behind Versus 13 before it became Final Fantasy 15, and wants to use the unexplored plans for the game to develop Verum Rex. Essentially, a lot of effort is going into Yozora's character, which gives credence to him being Re: Mind's secret boss and thus being important to the series in the future.
Kingdom Hearts 3 is out now for PS4 and Xbox One.
