Juno appears in Soulcalibur IV in Tower of Lost Souls both Ascend & Descend mode but in Ascend mode she is under the floor "Iron Sword" using Siegfried's style teaming up with Astraia and Thetis. She has very low defense, and can sometimes be killed in one hit with certain attacks.
Soul Calibur IV Skills & Details
Soul Gauge Boost C
TOLS Floor Ascend Mode: Iron Sword
Partners: Astraia & Thetis
Descend Mode: Floor 2-24 (Depending)