Wonder Girl's History
Cassandra Sandsmark is Wonder Girl, a member of the Teen Titans and Young Justice. She is the daughter of Lennox, making her a granddaughter of Zeus, the mightiest of the Gods of Olympus, and the niece of Wonder Woman.
Early life
Cassandra Sandsmark was born to archaeologist Helena Sandsmark and the demigod adventurer Lennox. Her father left when she was four, after which Helena and Cassie traveled the world from dig site to dig site. Helena became Archaeologist of the Year for five years in a row. Cassie learned much about archaeology and foreign languages, but this globetrotter lifestyle left no room for school or friends. In order to cope with her frustrations and lack of a normal life, she turned to crime. Wherever she went with her mom, she would steal art from museums and collectors.
Criminal career
At age 16, she met the art thief Diesel when he saved her from local police. Not having had any friends, she immediately fell for the impressive figure. The two started "dating" - Diesel would meet up with Cassie whenever she went on an expedition with her mother, and they would sneak off together, stealing art, meeting fences and business partners, and living in luxury hotels. Diesel called her his biggest treasure, and was uneasy that she still spent time on the dig sites.
Several months later, at a dig site near Angkor Wat in Cambodia, everything changed. Diesel had gone ahead and explored a dangerous section of a temple. When Cassie found him, he was being attacked by a liquid metal. Because she couldn't get it off, she searched for tools in the temple. She found two ancient bracelets, which turned out to be related to the metal. They transformed her clothes into armor, and gave her new insights into what the metal was. It was an alien parasite, and she knew Diesel wasn't strong enough to control it. She conned the metal to release him and choose her instead, but instantly regretted it, as she couldn't master it with ease.
Diesel was outraged that Cassie stole his biggest find, his ticket to greatness. Before he could attack her, the temple collapsed. Cassie escaped, but found no trace of Diesel. The disaster severely damaged Helena's reputation, and with it, her relationship with her daughter.
Cassie became a wandering thief, stealing from wherever she went. However, she kept most of it rather than fencing it off. The media had come to dub her "Wonder Girl", but she hated that name. She had no relation to Wonder Woman (to her knowledge), and was so intimidated by the woman she had never met that she was reluctant to use a name similar to hers.
Joining the Teen Titans
Cassie eventually moved to Hollywood, where she bought a little house and continued her crime spree. Her exploits had caught the attention of N.O.W.H.E.R.E., who were gathering metahumans for research. A few days before Halloween, she was ambushed on the coastal highway by a fake policeman. Red Robin, who had been tracking N.O.W.H.E.R.E., intervened. When he explained why he was there, Cassie was distrusting and reluctant. Not just because this metahuman-hunting organization now attacked a non-metahuman, but also because Red Robin was aware of her criminal activities. A renewed attack forced her to activate her armor. Though she defeated the attacking helicopter, she realized her life wouldn't be the same.
Cassie took Red Robin to her home, where he spent the night on the couch. He explained he was going to investigate other metahuman kids, but Cassie told him she was not interested in teaming up. She did decide to track his movements as he investigated Skitter, and saved him in an ambush by N.O.W.H.E.R.E. agent Thrice. She started doing more research into N.O.W.H.E.R.E., and enjoyed it.
Her research had made her a renewed target; N.O.W.H.E.R.E. ordered its prime agent Superboy to bring her in. On New Year's Eve, she was attacked in New York City. She held her own, and with the help of Red Robin and his new allies (Skitter, Bunker, Kid Flash and Solstice) they escaped. Superboy, realizing he'd been used, betrayed N.O.W.H.E.R.E.
Red Robin wanted to rescue Superboy from N.O.W.H.E.R.E., but the others didn't agree, after their fight earlier. Wonder Girl was the first to budge. At the secret facility where Superboy was held, Cassie defeated Ravager and Templar. Once they freed Superboy and tried to escape, they were captured by the villain Harvest.
The Culling
Main article: The Culling: Rise of the Ravagers
Harvest had been gathering young metahumans to have them fight in an event called the Culling to thin the ranks of your power users. This time, the Titans were up. In the Crucible, they quickly teamed up with the Legion of Super-Heroes and the Ravagers. Red Robin devised a plan for them; the Legion would go after the central power core while the Titans held off Harvest's mobs. Wonder Girl worked together with Superboy, though she still had issues trusting him. When the Legion succeeded, Wonder Girl proposed escaping. Harvest would live, but his resources and base were destroyed, so he was out of the picture for now.
Cassie and Kon escaped together and landed on an island infested with dinosaurs. The two didn't get off to a good start, as their alone-time immediately resulted in bickering. As time progressed, they became more comfortable with each other. Cassie still didn't open up about her secrets, and considered all friendliness over after Superboy tried to kiss her. They eventually regrouped with the others, and Danny the Street brought them home.
Return of Diesel
The more Cassie used her armor, the more difficulty she had controlling it. She suffered fits of rage, self control issues and occasionally blacked out. Her repeated use of the armor also allowed Diesel, who had survived the temple collapse, to track her down. One night, it went completely wrong. While the team was relaxing in their Lextowers base, the armor took over. She quickly defeated Bunker, Solstice and Kid Flash. Superboy and Red Robin lured her away from the city, and Superboy removed Cassie's armor with his telekinesis. Before she could recover, Diesel showed up, and absorbed the armor debris.
Determined to get the armor back, Cassie explained her history to her friends and lead them to Cambodia. Though Diesel showed he could control the armor, Cassie doubted that he would use the power for benevolent purposes. At the temple site, they discovered the armor was connected somehow to Trigon. They were attacked again by Diesel and an group of blood warriors. With no powers, Cassie left the warriors to her friends. She explained to Diesel she did everything because she loved him, and didn't want him to suffer. He didn't accept that, so Cassie used the ace up her sleeve: she had kept the lariat hidden, and used it to ensnare Diesel. It drained the life from Diesel, and he withered away. With no host, the armor returned to Cassie.
Lost friends
While Red Robin was away on personal business, Cassie stepped up to become leader. But on her first outing, she could do nothing but watch as H'el took Superboy. So when they discovered Red Robin was kidnapped by the Joker, she lead the team to Gotham City, desperate not to lose another member. They met up with Batgirl, who told them to leave as they weren't ready for Gotham. Wonder Girl decided to help either way. They teamed up with the Outlaws (Arsenal and Starfire) to distribute anti-Joker Venom vaccines to Jokerized mobs around Gotham. With that arduous task complete, she decided Batgirl was right, and waited for Red Robin to return on his own.
Trigon
The interdimensional demon Trigon had set his eye on Earth, and sensed the presence the Silent Armor. He planned to defeat the Titans completely and utterly by destroying their reputation and relationships.[1] He had Red Robin possessed, and used him to destroy the team from the inside. Red Robin showcased a slew of odd behaviors, which included seducing and sleeping with Wonder Girl. This "foreplay" heralded the arrival of Trigon in Times Square, which Cassie sensed through her connection with the Silent Armor. Wonder Girl charged into battle, but was quickly dispatched. As he held her, Trigon revealed he knew a lot more about her than she did, including who her father was. The other Titans, Beast Boy, Psimon and Raven joined the fray, which by now had killed dozens of people. Raven explained Trigon's plans.
Cassie and Bunker defeated Ruskoff, but the Titans were no match for Trigon himself. Eventually, Red Robin managed to wound him, which forced the demon to retreat. Raven explained that Trigon tested Red Robin by lowering his inhibitions, and revealed some of the things - seducing Cassie and the very much spoken for Solstice - which he had done. Knowing the behavior came from within Red Robin and he wasn't under mind control harmed the team spirit. Cassie was torn after the encounter. She questioned her feelings for Red Robin - she enjoyed the night, and was in no way resisting his seduction. However, she also liked Superboy, and confessed to him. The mystery of her father also weighed on her mind.
Lost in Time
When the Justice League was defeated by the Crime Syndicate, the Titans were looking for their own way to defeat them. It didn't go well: Johnny Quick and Atomica defeated them, and Johnny sent them into the timestream. They were bounced through several timelines before being sent to the near future timeline of Jon Lane Kent. Cassie tried to find out if that timeline's League knew about her father, but a fight between Kon and Jon interrupted her search.
In the hope that it would change the timeline, the future timeline's Gar Logan switched the wounded Kon with Jon. The next stop in the timeline was Kid Flash's own timeline, where the Teen Titans discovered he was a wanted criminal. "Superboy" was recuperating in a Echo Chronal Authority hospital, with Cassie by his side. When he woke up, he attacked her in confusion, but Wonder Girl easily beat him. She didn't realize something far worse was wrong with him.
Kid Flash's trial ended up in an all-out war, with the Titans taking neither side. In the end, he pleaded guilty, and Solstice joined him in his imprisonment on Takron-Galtos. Superboy also left the Titans in search of his own goals. With their numbers halved, Cassie wondered what would become of them. Red Robin encouraged her, and confessed his love for her, though he had bottled them up out of professionalism. With Superboy out of the picture, she caved in to Red again.
After getting back to their time, the three remaining Titans join Bunker, Beast Boy and Skitter in the fight against the Crime Syndicate, before stopping once and for all their old nemesis, Harvest. After this mission, for a certain period of time, the Titans disbanded.
Back with the Titans
S.T.A.R. Labs
Red Robin once again tried to make the Titans work, with Cassie one of the returning members together with Raven, Beast Boy and Bunker. Once again established in New York, the Titans work to stop Algorithm, an advanced A.I. that wanted to sabot S.T.A.R. Labs. Meanwhile, Cassie's mother, Helena Sandsmark, is afraid of what this new superhero life could bring to her and she is determined to make Cassie leave her new "career". But with the Titans rising to national fame, a group of girls assemble in New York, starting to patrol the street and fight crime in the name of Wonder Girl.
Helena soon came to New York, trying to talk to Cassandra, but the two were stopped from having any kind of confrontation thanks to Tim having to deal with Algorithm and sending an alarm to all Titans members. Still, when Cassie and the others get to the Manhattan facility of S.T.A.R. Labs where Tim was fighting, everything is all right and even better: a head functionary of S.T.A.R. Labs, Manchester Black, proposed to Tim an alliance plan between the Labs and the Teen Titans to legitimately make them a super-team, which Tim accepted communicating the news to the others.
Finally Cassie has a little more time to talk with her mother, who tells Wonder Girl how much afraid she is for her. During a chat walking in the district where Cassie lives, a girl falls from a roof and Cassie rallies to save her. What she does not know is that she's from a group of four punks who took a drug giving the users temporary metahuman powers, who of course they wanted to use for fun. As the girls from the gang Cassie inspired take care of Helena's well-being, Wonder Girl starts fighting the four kids, soon helped by the rest of the Titans.
When one of the kids discovers that Helena is Wonder Girl's mother, he tries to hurt her launching a whole truck over her. A girl from the gang apparently sacrifices her life to save Helena's, only to reveal herself as a super-hero, too: she's Tanya Spears, the new Power Girl. After handling the problem, the Titans offer Tanya a spot on the team, which she accepts, but soon her and Cassie start arguing with Tim about the direction the team is taking. The two girls start a friendship, and soon are confronted by Manchester Black who wants to make them the stars of the Teen Titans.
After the Titans stop a mysterious terrorist group from blowing up Manhattan, the team gets really famous, with them always contacted by the media and featured, willingly or not, in all kinds of videos on the web. As Tim Drake grows annoyed of all this noise around them, Black shows him a clip that sends a shock through the whole team: Kon-El, also known as Superboy, is back and has just perpetrated a mass-murder.
The Elite
Shocked by the news, Cassie and Tim argue about how they should handle the Superboy matter: still hurt by how Kon decided to stay in the 30th century, even if they started a love story, Cassie believes that Kon should be delivered to authorities as he was created to be a living weapon and was too powerful to live like a common teenager. For Cassie, the Titans could not help him the way he should be helped. Still, Tim brings him to New York, offering him help and making the Titans rogues: both Cassie and Tanya disagree on the matter, and accept the proposal of Manchester Black of joining a new, S.T.A.R. Labs-funded team of teen superheroes to bring the Titans to justice and finally act to protect people and deliver justice: Cassie Sandsmark is chosen as the new leader of The Elite.
Sent to Chicago to take Superboy into custody, Cassandra tries to resolve the matter peacefully , but soon a returning Kid Flash, also member of The Elite, triggers the fight between the two teams. Cassie and Kon fight each other, but the girl is unable to defeat her former lover: after losing her senses, Cassie regains consciousness knowing that Superboy escaped. Still, she tele-transports out of the city to the apartment of Manchester Black, where Red Robin and Raven teleported just a few moments before. But once again, The Elite arrives too late.
After being informed by Black that Tim and the Titans are heading to the M.A.W., a super-prison in Metropolis, to find Despero who could exonerate Kon from all accusations, the Elite sends Cassie and Bart in reconnaissance. Together with Tim and Kon, they all get abducted by a returning Harvest who convinces Superboy in following once again his cause. With the remaining three Titans held prisoners together, Cassie bonds once again with Tim and soon, after escaping Harvest's grasp and coming back to the M.A.W., Cassie also breaks his alliance with Manchester Black after Tanya discovered he set all of them up with a trap inside the super-prison and that he also experimented genetically on them to enhance their powers.
Who is Wonder Girl?
After defeating Black, the Titans are on the run, escaping authorities through the United States. During this time, Tim suggests to keep their powers shut, but Cassie struggles in doing so, also because he's hearing a calling from her father, a thing that disturbs her. Starting to bringing back bad habits, like stealing, Cassie argues a lot with Tim, reaching a breaking point: after confronting Raven on the matter of her disquiet, Wonder Girl goes to London alone, trying to pinpoint the location of her father. Raven, who feels the way her friend feels thanks to her empathy powers, tracks her and transports the rest of the team in London as well. There, the Titans face a group of hyena-and-man hybrids, while Cassie breaks into an apartment: in here, Wonder Girl finds only the head of his father, petrified. She's shocked, but soon the mistress of the hyena-men shows up: she's a demigoddess called Cassandra, and she reveals to Cassie that she's her aunt, sister to her father Lennox, and that Cassandra Sandsmark is not human, but a demigoddess herself, granddaughter of Zeus.
Cassandra wants to bring her niece with her, to resurrect her father and to give her the chance to be a goddess and not just a mere mortal. Finally feeling understood, Cassie accepts her aunt proposal and she gets tele-transported with her and the whole Titans teen, with the exception of Red Robin who was taken by the owner of the apartment: Wonder Woman. As Cassandra explains to her niece she and Lennox were not on good terms, after Lennox deprived her of her powers, and that she was part of the plan that brought Lennox to his death, Cassandra once again remarks that she's only pushed by her will of giving Cassie a chance to live her life better.
The mission is retrieving the Rod of Asclepius, an ancient item protected by Apollo that is capable of bringing someone back to life. Cassandra and Wonder Girl fight a gigantic snake, with Wonder Girl killing him while releasing all of her power, to the joy of her aunt. As they recover the Rod, Wonder Woman and Red Robin reach them, with Diana wrapping Cassandra with her Lasso of Truth. Diana is doubtful about Cassandra's true intentions, but the Lasso reveals she is telling the truth and that she really wants to help Cassie. Still, Wonder Woman tells them that using the power of the Gods without permission always comes with too high of a price, and counsels Wonder Girl to come with her to Mount Olympus to give the Rod back, after also revealing to Cassie that she's her aunt as well.
While discussing, Cassandra and Wonder Woman start a fight with the Rod falling inside a crater: the Titans recover it and give it to Cassie, telling her it' her choice to make. Cassie trusts Cassandra, giving her the Rod and expecting her to bring Lennox back, but her aunt uses the Rod to heal her throat, getting back her powers: the ability to control mortals with her voice. Horrified, Cassie cannot explain herself how her aunt tricked Diana's Lasso, and Cassandra explains her that before her powers faded away, she used them to impart an order to herself: do anything to bring your powers back, including believing with all her heart in a lie.
Cassandra tried then to kill all the Titans with a command, but Red Robin and Bunker counter her and open a window of opportunity for Cassie: repeating history, she rips her aunt's throat depriving her of her powers once again. Then, she uses the Rod once again, before its self-destruction, to heal Cassandra's throat but without bringing her powers back. Wonder Woman is impressed and joyful about the choice Wonder Girl made, and after capturing Cassandra, Diana proposes Cassie to come with her and know her family better. Cassie is honored, but tells Diana her family are the Teen Titans. Once again impressed by Wonder Girl, Diana leaves with Cassandra still telling her newfound niece that she can call her whenever she wanted, either for questions or for help.
Death of Tim Drake
Cassie lives more adventures with the Titans, like stopping the Church of Blood, fighting Amanda Waller in Belle Reve after she tried to recruit the Titans inside the Suicide Squad and clashing with the H.I.V.E. Queen as she tried to take over New Orleans. But a shocking death destroys the reality of the Teen Titans and of Wonder Girl herself, when Tim Drake is killed by the Colony in Gotham, fighting alongside Batman and the Gotham Knights. Without their leader, the Titans gather to remember him before his funeral, with Cassie telling about how great it was to work with him and how Tim had the incredible ability of making anyone around him better. He then tried to think how Tim's girlfriend, Stephanie Brown, was feeling right now, as she once was in love with Red Robin herself. After this touching moment between friends, the Titans are no more as Tim was the one who was holding them together. In the end, Cassie and Tanya swear they will continue to fight crime and evil as Wonder Girl and Power Girl.