Soul Dancer first appears in the Arqa Block of Tartarus. It will usually be alone or in groups of three. In The Answer, they will be summoned by the Brilliant Cyclops as back up. They will then appear in the first section of Caina within the Abyss of Time as a normal encounter.
Soul Dancer appears on the first four floors of Marukyu Striptease in the Midnight Channel. It may drop the Passion Clasp material after being defeated. Selling 6 Passion Clasps at Daidara will unlock the Tesseb weapon for Yukiko in the shop's inventory.
Once Quest #18: Carbon Copy is accepted, Soul Dancers are the Shadows to defeat in order to acquire the Flower Brooch.
In Golden, it may also drop Smoky Quartz for trade at Shiroku Pub.
Soul Dancer appears in Act 3 of Hikari. It attacks with heavy, single-target Physical skills. When defeated, it may drop Dancer Gem and Dancer Balloon. Dancer Gem is used to create the Azoth Dagger for the P5 hero, the Fengshen Whip for Ann, the Lethe Axe for Haru*, the Trident for Ken, the Magical Gun for Naoto, and the Rune Dress female armor.