Cassandra Sandsmark was originally the daughter of Olympian God Zeus and Dr. Helena Sandsmark. She became the second Wonder Girl in an attempt to save Wonder Woman's life. Cassie continues adventuring as a member of the Teen Titans. Her New 52 incarnation is the daughter of Wonder Woman's half-brother Lennox, and derives her powers from an ancient armor named the 'Silent Armor' related to the demon Trigon.
Powers and abilities
Cassandra originally received her powers from a number of mystical artifacts employed by Artemis during her time as Wonder Woman. These included the Gauntlet of Atlas and the Sandals of Hermes, which provided her with the powers of strength and speed/flight, respectively. She was eventually granted similar abilities by Zeus as "her fondest wish". Discouraged by previously shown arrogance in his children (Ares and Heracles), Zeus also blessed Cassandra's mother with the ability to take away her powers for a short time via a simple touch.
Shortly after joining the Teen Titans, Ares approached her and gave Cassandra her own magic lasso. Unlike Wonder Woman's Lasso of Truth, Cassandra's is a weapon which channels Zeus' lightning when she becomes angry. When the Greek gods left the mortal plane as a result of the events of Infinite Crisis, taking Cassandra's powers along with them, Ares offered her some of his power, saying that she would be "more powerful than [she's] ever been". What this entails is not made entirely clear, though she appeared to have retained all of her former abilities
In other media
This character appears in the cartoon Young Justice.