Yvenna was a student at Cheiron's Academy with Hercules, with whom she had an uncomfortable relationship, due to their mutual attraction. After Jason began recruiting people for his quest for the Golden Fleece, she revealed that her Uncle owned the Argo and so she was made part of the Argonauts on their hunt for the Golden Fleece.

During this time, she revealed to her friends her reason for joining the crew: years ago, her home village had been attacked by raiders, and that although she and her people had fought bravely, they had been forced into slavery, with her the only one to escape. She now wished to save her village with the help of the Fleece. She later revealed privately to Hercules that this was only partially the truth: she had not fought to save her village, but had in fact, run away and hid in the woods while it was attacked. She believed that if she could prove herself worthy of retrieving the Fleece, then she would be ready to return and save her people.

When the Argonauts landed on the island of Discord, they were infected by the Goddess with violent and sexual desires, and Yvenna and Hercules nearly had sex while under her influence. However, Yvenna attempted to stab him with a knife, and he knocked her out. After they were cured, she and Hercules seemed to have begun a tenuous romantic relationship.

In order to retrieve the Fleece, the Argonauts had to fight a giant named Talos who was under Ares' command. In order to distract the giant in order to give Hercules the opportunity to kill it, she took the Fleece, and distracted the monster from atop a house in the village. However, she was unable to compete with his sheer power, and was mortally wounded when he knocked her off the house. Despite attempts to save her with the Fleece, she died of her injuries, but not before Hercules told her that she was a hero, and she begged him for a promise, but died before revealing it. Hercules later came to believe that her wish was for him to save her village, which he set off to do in memory of her. ( Young Hercules).