For those who have not completed games in the Xenoblade Chronicles series, this page contains spoilers regarding the plot. Discretion is advised.
Riveral Ansels are enemies in Xenoblade Chronicles 2. They are members of the Ansel family, and can be found at level 57 - 59 at the 7th Perimeter Skyport in the World Tree. Five of them must be defeated to unlock Vale's level 4 "Tainted Palace", Azami's level 5 "Decadent Finale", Nim's level 5 "Wild Familiars" and two for Elma's level 5 "Focus".