Nil

Nil is a difficulty on both the JToH and SToH charts. It is the final difficulty before the Why+ category, represented by a dark grey color. It’s a popular difficulty in SToH due to Citadel of Void being at this difficulty. Most CoV remakes in SToH are at this difficulty. Basically nobody can beat towers here.

Towers/obbies at this difficulty
Tower of Quantum Nexus