Gwen Tennyson (Classic)/Ben 10

In the Original Series, Gwen went on a road trip with her grandfather Max and her cousin Ben. She and Ben constantly argued (like about Ben misusing the watch or about Gwen's powers). However, they were shown to deeply care for each other. Gwen also showed deep affection for her grandfather.
Gwen also used newspapers and her laptop to research any strange people and creatures they came across. She was a capable gymnast and has had some training in martial arts.
She was depicted as snobbish due to her young girl attitude. Overall, her most notable skill at this time was her innate, if latent, ability at magic. Having within her what Charmcaster called a "magical aura", Gwen was capable of using various magical artifacts, charms, talismans, and spells. When using the magical, luck-giving Charm of Bezel, she was able to activate it instinctively, whereas Hex could not. Later on, when she took and used his staff, she was able to make it fire a yellow-colored energy blast. According to Charmcaster, only someone of Hex's skill should have had that ability.
Gwen started tapping into magical powers when she procured a small book of spells from Charmcaster in the episode A Change of Face. On two occasions, Gwen used the Charms of Bezel's incredible and unique powers and abilities to become a superhero by the name of "Lucky Girl". At first, her ability drew from the luck-granting, Charms of Bezel, which innately gave her perfect luck and the abilities and powers of probability manipulation. While wearing the charm, any action she took would result in a Rube Goldberg-style chain reaction benefiting her original intent, but usually injuring Ben in the process. She later brought back her superhero identity after obtaining the legendary Keystone of Bezel, which greatly strengthened and increased her natural abilities to superhuman levels rather than just affecting her luck. Both times, Gwen was forced to retire when the Charms of Bezel were destroyed. 
In Perfect Day, a superhero form was given to her by Ben as a form of petty torment while they were inside Ben's dream battling his imaginary bullies. In this form, she only exhibited the power of enhanced biting. Ben called her Ultra Rat.
Gwen formed a rivalry with Charmcaster during the series.