Lugh

Lugh (ルーグ, Ruugu), otherwise known as Ildanach (イルダーナフ, irudanafu), Lug, or Roog, is a demon in the series.

History
Lugh Lamfada or Lugh the Long Hand, the name Long Hand came from his long spear, Brionach. The great sun god of the Celts, also called Ildhana. Grandson of Balor and killed him in the great war between the Tuatha D'anaan and the Formorians. He fathered Cu Chulainn with Dectera, daughter of the Ulster's chief druid, Cathbad.

Appearances

 * Giten Megami Tensei: Majin Clan
 * Majin Tensei II: Spiral Nemesis: Genma Clan
 * Persona 2: Innocent Sin: Sun Arcana (as Ildanach)
 * Persona 2: Eternal Punishment: Sun Arcana (as Il-Dana), Emperor Arcana (as Lugh)
 * Devil Summoner: Soul Hackers: Majin Clan
 * DemiKids: Light Version as Roog
 * DemiKids: Dark Version as Roog
 * Devil Children Fire Book
 * Devil Children Ice Book
 * Devil Survivor 2: Deity Race

Devil Survivor 2
Lugh is the demon that acts as the key to allow the Dragon Stream to take a different form. However, due to the Void's advance, his body is damaged, and a medium will be required to channel his energy. Based on the Demon Tamers' health screening results, Io is most suitable to be Lugh's medium. However, once Lugh is unsealed, his energy scatters across the map, and the party must gather all the pieces of his energy (or recover them from thieving demons) before demons can take them away.

When Lugh's energy is sent to Io, Yamato begins the ritual for the unsealing of the Dragon Stream, where Io is synchronised with Lugh. The ritual proves to be strenuous, and the player has to regularly heal Io and defend her from interfering demons. Once the ritual completes, Io unleashes the Dragon Stream on Mizar. Depending on whether the player chose to comfort Io prior to the ritual, the strain from channeling Lugh may end up taking Io's life.

If the protagonist does not support Daichi and Io is still alive by the 7th Day, Io channels Lugh during the fight with her and Daichi, complete with her race and Racial Skill changing to match Lugh's. After the player defeats her, Lugh is unlocked as a Unique demon for fusion in the Cathedral of Shadows. Lugh does not require a special combination of demons.