Not much is known about Kareena, she is Venger's sister and appears in the episode Citadel Of Shadow. She appears as an innocent girl who calls for help. Hearing her, Sheila and Uni go to her aid. As Sheila saves Kareena, she says that she has to take back a red ring that her brother stole from her and locked in the Citadel Of Shadow. While Sheila is trying to take the red ring, Kareena suddenly reveals to Uni an evil personality of hers, as she prevents Uni from screaming and calls Sheila back. When the others find Sheila and Kareena at the Citadel, Venger appears to imprision her again, and its revealed who is her evil brother. With the red ring, Kareena defeats Venger and then asks the heroes for the blue ring, Dungeon Master however, does not allow them to give her the blue ring and orders her to leave. The heroes however, had to take her red ring back, for the two rings would open them a path to home. As they arrive in Venger's castle, where Kareena is, Sheila confronts Kareena and manages to steal the ring from her. However, when she is about to open their path to home, Sheila hears Kareena screaming, imprisioned by Venger. She runs to save her and throws the two rings at Venger: the red ring keeps Venger from moving, while the blue ring is destroyed and turns into a temporary prision for Venger. Its also revealed that Kareena's evil personality was an effect of the blue ring, and its gone when its destroyed.
Based on an unfilmed ending for the series, it seems likely that Kareena, being Venger's sister, was also the child of Dungeon Master.