Eriel is fighter who uses Hilde's fighting style and she appears in Tower Of Lost Souls ascend mode under the floor "Time To Trifle".
Tower Of Lost Souls Details & Skills
TOLS Ascend Mode Floor: Time To Trifle
Partners: Hernes & Siegfried
Skills: Nullify Ringout A
Soul Gauge Recovery S
HP Recovery S
Auto Grapple Break S