In the Animation, when the events of the M’arrillian Invasion effectively began, Phelphor mind-controls the Guardians of the Deepmines Vinta, Junda, Tartarek and Nauthilax himself so they could open the Doors of the Deepmines for him. As for Nauthilax, comes into play, the Tainted.
Surrendered to the power of the M’arrillians, Nauthilax loses his only Elemental affinity as well as his role as Elementalist because given his expertise with underwater espionage, becoming a Scout is a much more advantageous for his new masters. Even though having his Recklessness taken away is very seductive, internally, Nauthilax constantly struggles against the mind-control and the effort employed fires back Exhausting him, reducing all of his Disciplines whenever he attacks.
Regardless, although he didn’t become more resilient nor smarter either, as a M’arrillian Minion Nauthilax became very powerful, a perfect aide to a new secondary ability which grants him instant mastering of a new Element whenever his enormous Power becomes more evident while in combat.
However, when commanded by a M’arrillian Chieftain, Creatures capable of brainwashing other Creatures, Nauthilax’s abilities change once again to better suit the Captain, so no matter what it takes, he can focus on causing as much damage as possible. A commitment like this invariably would make him Reckless again, but also would allow him to Outperform his own limits, causing even more damage by showing off his Power and, provided he managed to control this destructive magnitude, even utterly annihilate his enemies’ Battlegears.