The Chrono Cross Condensed Plot Summary has been updated with the abandoned storyline postulated by Chrono Cross Ultimania. You can read about their theory at the article; or, you can simply check it out below. We are now in our second Radical Dreamers Week; stay tuned in February for the biggest surprise the site has known in recent memory.
"The story above may not be the plot as originally intended for Chrono Cross. Signs point to another overaching storyline that involved Serge binding with the Time Devourer itself; in this scenario, Serge, if he did not defeat the Time Devourer with the Chrono Cross, would ultimately bind with it and cause the Devourer to mature, granting him the power to consume space-time. Chrono Cross Ultimania mainly supports this notion, claiming that the Arbiter of the Frozen Flame must mediate between his fellow lifeforms and Lavos, or else he will inevitably bind with the creature and spell destruction for other humans. Ultimania also postulates that Schala was an Arbiter of the Frozen Flame while it existed in Zeal, and that is how she came to bind with Lavos. Apparently, the Time Devourer needed enough power before it could reach maturity, and Serge would have been the final piece in the puzzle. Quotes in the game also seem to hint at this possibility; three come to mind specifically. A demi-human in Marbule states that "anyone who touches that Flame will become a different being." Lynx, at Viper Manor, warns Serge that "there shall be a deep enmity between you and the world" once destruction occurs. Lastly, Belthasar notes that the Arbiter will gain "extraodinary powers...by binding with the new seed of destruction, the Devourer of Time." However, this storyline is not directly stated or implied in Chrono Cross, and neither has series creator Masato Kato confirmed it himself. For the time being, it remains speculation made by the Ultimania authors. Considering that in the same book, they contradict other canon (such as stating the Prometheus Circuit is not RObo, when Masato Kato noted that the circuit is Robo), the veracity of Ultimania is arguable."