"Isren" was the alias of an aged male Evereni who went by the Evereni word meaning "old uncle" rather than his name. At some point no earlier than 379 BBY, he was on the Outer Rim world Ryloth, hunting native creatures known as lyleks in the planet's equatorial forests. During his stay on Ryloth, he visited a bar located in a hub near the forests, where he met the Evereni pirate leader Marda Ro. Ro—having grown up outside Evereni culture—was curious about her species' culture and Isren indulged her interest and taught her about Evereni culture and history.
Ro later recalled Isren's lessons after her human assistant Alirya died. Soon afterward she mentioned him in a conversation with the Evereni Velya Faer and also talked about her encounter with him in a message she recorded for her descendants, which her great-great-grandson Marchion Ro had listened to by 252 BBY. Ro listened to his great-great-grandmother's memoirs again in 228 BBY, and recalled that they recounted her hunt for Isren.
On Ryloth, Isren met Marda Ro. (pictured)
"Isren" was a male Evereni who was present on the Outer Rim Territories planet Ryloth, hunting creatures known as lyleks in the world's equatorial forests. He stayed on Ryloth for at least one month and at some point no earlier than 379 BBY, he visited a bar located in one of the hubs near the equatorial forests at the same time as the pirate leader Marda Ro—an Evereni who was searching for others of her species.
She approached Isren while he was leaning against the wall with a bowl of hot liquor in his hand. He commanded her to sit and started speaking in the language of Evereni, but switched to Basic as Ro did not speak Evereni. He refused to tell Ro his name, introducing himself with the Evereni word meaning "old uncle" instead. Isren shared his liquor with the Evereni girl and taught her about Evereni culture and their origins on a planet of storms. Ro bought him meat and soup and in return Isren bought her more liquor. Their conversation convinced Isren that Ro is a legacy of the Evereni and he told her to make her visions come true, but ultimately refused to join her and they parted ways.
Through Marda Ro's journal, Marchion Ro (pictured) learned about Isren.
Ro would eventually track down the Evereni twins Vika and Velya Faer. During a feast aboard her starship, the Gaze Electric, Ro's human assistant Alirya attempted to kill Vika, instead dying herself at the Evereni woman's hand. In retaliation, Ro killed Faer herself, and following the altercation she remembered Isren's lesson to not trust anyone. Despite his initial rage, she calmed Velya down and convinced him to take the place by her side that was formerly Alirya's.
Later, Ro and Velya talked about Evereni they had met. Ro brought up that Isren did not even tell her his name and wondered whether that meant he thought she did not matter, but Faer suggested that maybe Isren did not think he mattered instead, and did not wish for his name to by remembered by his people. Ro also recalled that Isren told her Evereni meet only in death, and Faer explained that they also meet in the Rystan system.
At some point, Ro recounted her meeting with Isren in a journal entry she recorded for her descendants. By 252 BBY, during his youth, Ro's great-great-grandson Marchion Ro had listened to her recordings, including the messages where Isren was mentioned. In 228 BBY, while listening to the journal again, Ro remembered that the journal's contents chronicled his great-great-grandmother's hunt for Evereni, including Isren.
Unlike some other Evereni, Isren saw ghosts of beings who were going to die rather than those who were already dead. During his conversation with Ro, the only thing he had admitted to trusting besides himself was legacy. He was fluent in the Evereni language and while he knew the meaning of Ro's family name, he refused to tell her. As an Evereni, Isren had dark gray skin and black eyes. As a result of aging, the skin around his eyes was wrinkled and his black hair was streaked with red. Isren's hair was pulled back, revealing ears that had earlobes pierced by bones with gilded tips.
Isren wore forest fatigues and carried three visible weapons. Ro suspected that he also had additional, concealed weapons on him.
Isren appeared in a flashback in the short story "A Closed Fist Has No Claws," written by Tessa Gratton and published in the 2023 young-adult anthology The High Republic: Tales of Light and Life as a part of the Star Wars: The High Republic multimedia project. In an interview, Gratton talked about how he knew they wanted an Evereni who rejects Marda Ro and another one who embraced her, these being Isren and Velya Faer respectively in the final story. She also mentioned that he thinks that due to the pain she carries with her, Ro interprets her experiences with other Evereni she's met—such as Isren—painfully, taking the wrong lesson from them instead of interpreting them in a beautiful way.