Illuria (Lunar Veil)
The Last Dragon roams around the lunar tree
The Illuria is a Large Biome generated by the Lunar Veil Mod. It can be found on the far right side of the world in the sky.
The massive tree is mainly comprised of Illuria Dirt, Illuria Grass, Illuria Wood, Illuria Leaves, and Bones. Ambient trees of various sizes can also be found while scaling up the massive tree as well.
Niivi can be found roaming around the Illuria, flying around during the daytime and sleeping during the nighttime. If damaged enough, she can drop Illurine Scales.
Illuria Outposts
The Illuria's people hide underground
The Illuria Outposts are small structures found in the underground Jungle and by extension, the underground Virulent.
The outposts are mainly comprised of Illuria Wood with a single small Illuria Tree in the middle. In the middle there is also a passageway to a chest that's unlocked after Plantera is defeated.
The main content of the outposts is unlocked after Plantera is defeated. Illurian Guards and Illurian Mages start spawning inside of them being one of the main source of Illurine Scales as well as the chest at the bottom being unlocked.