After Dark-Killer's defeat, Grigio was sent back to Earth in order to protect Ayaka City, thus being absent from the New Generation Heroes' pursuit of Tregear during the cold opening of Ultraman Taiga.
With the exception of Zero Darkness, all initial three copies were killed by their respective templates, wielding the power of Ultraman Zero.
As he was revived, Dark-Killer resurrected Etelgar and Lugiel to his cause and threatened the safety of X, Geed, Zero and Grigio, forcing Taro to recruit the New Generation Heroes in his fight.