Ardent Dancers appear in groups in the 7th through 9th Chapters of the Void Quest within the Midnight Channel. They alternate between attacking and using Garulas and in the 9th Chapter they may be accompanied by a Protective Lexy which will buff them with Tetrakarn and Makarakarn if given the chance. Upon being defeated, they may drop the Blade Metal material. Selling 10 Blade Metals at Daidara will unlock the Anglaise sword for the protagonist in the shop.
In Golden, it may appear in Chapters 5 through 9. It may also drop Milky Quartz for trade at Shiroku Pub.