Survival Duels, known as Disclosure Duels in the Japanese version (or Des Duels, a pun on Death Duels, for short in Japan pronunciation) are mandatory Duels issued by Thelonious Viper at Duel Academy. Bio-Bands were used to drain both the victor and loser's energies upon the conclusion of the Duel. It is the skill system for open duels regardless of dorms or grades.