Derris-Kharlan is a major planet and central plot point of all games in the Aselian timeline.
Tales of Phantasia
Derris-Kharlan, localized as Derris Karran in the Game Boy Advance version of the game, is an area in Tales of Phantasia, as well as the home planet of central antagonist, Dhaos. After losing its World Tree in a bloody war, it began suffering from mana depletion and required a Mana Seed to heal itself. Because of this, the people sent Dhaos into space to find another planet with a World Tree that could bear them a such a seed, and the planet he found was Aselia.
Tales of Phantasia: Narikiri Dungeon
Derris-Kharlan is an area in Tales of Phantasia: Narikiri Dungeon visited by the party through the usage of the "Cloud Painting". After completing one of its dungeons and defeating the guardian spirit, the spirit will reveal a series of flashbacks that give insight as to what crimes Dio and Mell committed in their past lives. From these flashbacks, it is possible to tell that the planet was destroyed by a war between two continents: Palace Gudora and Palace Sedamyu.
- Muspellsheim, Country of Fire
- Niflheim, Country of Ice
- Jotunheim, Country of Giants
- Nidavellir, Country of Dwarves
- Hel, Country of Death
- Bifrost, Bridge of Heaven
Tales of Symphonia
Derris-Kharlan is a third world in Tales of Symphonia. The planet is a giant comet comprised mostly of mana and is said to once have been the home of the elves before arriving at the world of humans, where the elves moved, living together with the humans. Derris-Kharlan was a giant comet that came from the depths of space, bringing the elves and the Giant Kharlan Tree with it. When Martel Yggdrasill died at the end of the Kharlan War, Mithos Yggdrasill, Kratos Aurion, and Yuan Ka-Fai made Derris-Kharlan their main base for Cruxis and separated the world into the planets of Sylvarant and Tethe'alla—4,000 years prior to the events of Tales of Symphonia.
With the help of the Eternal Sword, Derris-Kharlan is protected with a force field emitted from the legendary sword. With the aid of the force field, Derris-Kharlan is unaffected by both Sylvarant and Tethe'alla's gravity fields and also remains transparent to the people in both worlds below. The only way to reach Derris-Kharlan is via the Tower of Salvation. In Tales of Symphonia, Derris-Kharlan forever hangs in the sky high above the two parallel worlds, Sylvarant and Tethe'alla. When Lloyd Irving and his companions kill Remiel in order to save Colette Brunel, Kratos appears and informs them that it is too late, and that the angels of Cruxis will now take the Chosen of Mana to Derris-Kharlan as a vessel for Martel. This is the first time Derris-Kharlan is mentioned. Later, it is explained by Yuan that Derris-Kharlan is Cruxis's main base, where they are plotting the revival of Martel.
Welgaia, the Holy City, is a city populated entirely by angels and serves as the main base of Cruxis. The only way to enter the city is through the Tower of Salvation. It is filled with high technology and computers that serve as archives. Welgaia is visited twice by Lloyd and his companions. They first enter the city to find a "Mana Fragment" to cure Colette's Chronic Angelus Crystallus Inofficium. On their way, they are captured by Kratos and thrown into jail. Regal Bryant is able to free them using a technique with his hands, and they escape into the city, pretending to be Colette's prisoners. They eventually receive a fragment of mana after claiming they are couriers for Kratos. After learning the nature of Derris-Kharlan and Mithos's "New Age" project, they escape through the Tower of Salvation back to Tethe'alla. The group later returns to Welgaia on their way to prevent Mithos from forcing Derris-Kharlan from its orbit around the worlds of Sylvarant and Tethe'alla, which would leave both worlds to die due to the loss of mana generated from Derris-Kharlan itself.
After one of Lloyd's companions is possessed by Mithos and taken to Derris-Kharlan, the group follows them before being caught in a trap, finding themselves separated throughout Welgaia. Lloyd finds his possessed companion and releases them from the spell. Together, they find their other companions, who are imprisoned in pairs and scattered throughout the city. Mithos, in spirit form, uses the weaknesses of each character's heart and mind to create inner struggles, but their trust in Lloyd allows them to resist Mithos's psychological games. When everyone is reunited, they find the "Derris Emblem", which is the key that allows them to enter Vinheim.
Vinheim is Mithos's castle, located in the depths of Derris-Kharlan. The interior of the castle contains two spiraling staircases, a balcony, a throne room, a lounge, a library, and a rooftop-connecting bridge. It serves as the game's final dungeon and location of the last battle. The mandatory part of the castle is short and consists of passing through the entrance room, defeating a dragon guarding a large door, and entering the throne room where Mithos awaits. However, hidden in the castle are various powerful weapons and armor, as well as the Past and Future Stones. By finding these stones and completing a puzzle, it is possible to obtain the "Sacred Stone". This stone allows the group to teleport back to the Tower of Salvation and Forbidden Anamnesis, which can be accessed through the "Forbidden Tome of Demon Lords" in Sybak's library.
- The names of Derris-Kharlan's countries derive from Norse mythology:
- Muspelheim is a realm of primordial fire and one of the Nine Worlds
- Niflheim is a realm of primordial ice and also one of the Nine Worlds.
- Jotunheimr is the homeland of giants.
- Nidavellir is the homeland of dwarves.
- Hel is a being who presides over a realm of the same name, where she receives a portion of the dead.
- Bifrost is a burning rainbow bridge that reaches between Midgard—the world—and Asgard, the realm of the gods.