Haggarium seen in Defenders of Arus
Haggarium is a new type of dark energy in the Voltron Universe.
Fiction
Voltron Force (TV series)
Haggarium is the essence of Haggar and was harness by Maahox from the Hagger Quasar.[1] Haggarium is now used in all of the new Robeasts, also it can power up machines and weapons. Haggarium can drain the mystic energy that powers the Voltron Lions, the only thing that can combat it is Vince.
Trivia
It might possible that Haggar must have died before a year prior to the events of Voltron Force.