This section applies to the ILCOE.
Chaletwo is one of the two most powerful legendary Pokémon in the world, along with Molzapart. He is a true immortal and has the role of the Preserver, meaning he can travel through time, and he appears every year in the grass outside Green Town on the twenty-fifth of May at 4:26:45 PM. The Green Town Pokémon Festival is built around and climaxes with Chaletwo's arrival.
After the last War of the Legends, the first work of Mew, the Creator, was to attempt to create a successor to Chalenor by combining the energy left in Chalenor's eye with the nearest available whole body, Mewtwo's. The result was Chaletwo, who looks like Mewtwo but has Chalenor's deadly gaze.
Shortly after his "birth", Mew explained to him that he was the Preserver, with the role of protecting life in the world, and that he was created to succeed the previous Preserver, Chalenor, who was a good friend of Mew's but was killed in the War. After this, the two of them worked together on the recreation of all life (after Mew had temporarily imbued him with part of the Creator's powers), starting with the legendaries. Though Mew insisted on doing most of the work of creating the legendaries, Chaletwo wanted to make some on his own to prove that he could, and therefore he created three dragons in secret, Thunderyu, Volcaryu and Polaryu, which he made to despise one another. He then sealed them away in three caverns, keeping them asleep while waiting his time to bring them out and prove that he was just as good a creator as Mew was.
He grew out of these childish ambitions before he ever woke the dragons, however, and merely continued to keep them asleep all these years, eventually mostly forgetting about them.
One day he discovered his powers were gradually weakening. After talking to Molzapart, who he was vaguely friendly with at that point, it turned out Molzapart was losing his power as well. They asked Mew about it, and Mew revealed that the next War of the Legends was drawing closer, and the so-called Destroyer was draining the energy of all the legendaries in order to later drive them insane and cause a bloodbath similar to that in which Chalenor was killed. When Molzapart and Chaletwo wished to do something to prevent it, however, Mew refused, saying that you can't fight fate and so forth. Instead, they went behind Mew's back and talked to the other legendaries, but Mew had forbidden them to tell anyone about the War, on the basis that chaos would arise if the legendaries knew about it. Thus, they only said that for unspecified reasons, it was vitally important to have them all captured in Pokéballs before the War could begin, and naturally, most of them were skeptical, especially upon hearing Mew had also refused to participate. Instead, Chaletwo hatched a plan to recruit human trainers who would try to forcibly capture all of the legendaries. At first Molzapart did most of the work, but had little success; five years before when the War was expected to start, Chaletwo therefore took over, using the extreme measure of publically killing one trainer during his annual appearance (Leah Donaldson) after picking her out as the one who, out of the trainers in the group, seemed the most interested in the idea of capturing legendaries. After explaining it to her consciousness in a void of nothingness where they couldn't be overheard, Chaletwo resurrected her again and sent her out to look for the legendaries. She was remarkably successful, and Chaletwo proceeded to do the same in the following years in the hope that this way would recruit better trainers.
Chaletwo is one of my absolute favorite characters to write. This is because I find him adorable, according to my definition of "adorable" which means roughly, "He has psychological issues and doesn't know it but acts in a way that reveals it and I can look at it and go 'aww, look at his issues!'"
Said issues? Mainly, the constant need to prove himself to Mew. When he was young this manifested itself in creating the dragons, and now in his taking the initiative to save the legendaries from the War, which is partly a purely selfish longing to survive and partly a Freudian longing to be the one to save Mew's life and have Mew be indebted to him, both cloaked under the pretense of saving the world in general (there will always be a Creator to keep the world going, and most of the people and ordinary Pokémon are just resurrected provided their bodies aren't too damaged, but Chaletwo has convinced himself the War of the Legends is the ultimate end of the world anyway and that that's why he's concerned). Essentially he is still a teenager trying to rebel against his "parent" while simultaneously seeking its approval.
He also has a very torn view of Chalenor, because in his mind Mew hates him for not being Chalenor. This manifests itself both in Chaletwo having decided that Chalenor is an unreasonable standard to hold anyone up to because Chalenor was perfect (the way Mew speaks of him, anyway), and therefore doing his best to uphold that "perfect" image of Chalenor ("Don't you dare insult Chalenor in my ears!"), and in him being sort of bitter at being the Preserver and created from Chalenor in the first place because he feels otherwise he wouldn't be held up to that impossible standard, hence for example his "some crap like that" in response to the question of what the Preserver is supposed to do.
Finally, there is his obvious fondness for his early creations, the Dragons of Ouen, despite condemning his own stupidity in creating them in the first place and recognizing how dangerous they are. This I also find adorable, hence my writing so much of it around the entire dragon arc. Part of it may be that it is ever so slightly like my own insistence on writing and finishing this barely salvageable wreck of a fic. *cough*