This article describes a custom creation, custom theme, or other fan material, made by a Brickipedia contributor. It has never been, is not, and will not be officially released.
Ouroboros is a set in Ninjago: Threat From the Past theme.
This set includes 6 Minifigures, The Shrine of The Great Devourer, Obsidian Shurikens Of Ice and A Cell.
The place is appearing in chapter 113 and 114