Alister Silva is Terrence's antagonistic brother. He had come to clashed against Terrence time and again to gain something that Terrence "took away from him" and that is the position as the Dragon Halfa.
Alister is the son of Manfred Silva and Kim Lin Silva and the brother to Terrence Silva, Brandon Silva and Nique Silva. He was present on the day one is chosen to be the Dragon Halfa, the position he dreams of attaining. But his youngest brother, Terrence, was chosen to wield such a title. This caused him to develop envy and bitter hatred towards Terrence and wishes to annihilate him.
He is responsible for various tragedies and horrors that take place in Terrence's life.
1. The death of Nique, his own sister as well as his parents.
2. The creation of Nerokage, Terrence's evil counterpart, who the dragon halfa comes to clash with again and again
3. Corrupting his brother, Brandon.
4. The creation of the Evilras
He first appeared in "Body Change" where he fought Terrence and eventually gained his genetic materials needed for his evil plot. He used Terrence's genetic materials to turn himself into a dragon halfa like Terrence.
In a two parter, "A Brother's Hatred" he captured the Guardians, including Sirius and Tsunade to lure Terrence. He first tried to use the Evilras to destroy him. But eventually, the brothers clashed. Alister revealed his dragon form as some sort of a horrifying winged naga-like dragon. But Terrence eventually defeated Alister.
Alister was then seen lamenting his mistakes and was eventually institutionalized
In the final episodes of the sequel series, he appears serving his ancestor, Tajor Silva. During the climax he battled Terrence one last time and was killed.
In the final apearance of the movie, Majestic Guardians Movie: Lucemon Returns, He along with Tajor and Tzekel-Kan was brought back to life thanks to Lucemon, but he and the two were absorb by Lucemon.