Tesleen is a Hume with long blonde hair and light brown eyes. She wears a gray glade tunic with a small gray bag on her waist. She wields a bronze longsword in battle.
Tesleen is the lead caregiver at the Inn at Journey's Head, she cares greatly for her patients and keeps a positive attitude even though her job is a somber one. She is great friends with Alisae, and ever since the Warrior of Light's arrival she often teases Alisae for how much she admires them.
When she was a child, Tesleen and her ailing mother traveled to Amh Araeng to seek refuge at the Inn at Journey's Head, before her mother turns into a sin eater however she is given poison so that her passing is a peaceful one. Since that day, Tesleen decided to take care of the other patients who have been corrupted, so that they can live out their final days in peace.
When the Warrior of Light arrives in Amh Araeng, Tesleen asks them to escort her to the Inn. The corrupted patients sense the presence of a Sin Eater nearby, and Halric, a boy with corruption at an advanced stage, goes to it. The Warrior of Light and Alisaie find Halric before the Sin Eater known as the Forgiven Dissonance. Tesleen attempts to defend him, but is stabbed by the creature. She wants Halric to live on, but succumbs to her wounds and transforms into a Sin Eater herself. With what little control she has left, Tesleen apologizes to Alisaie for the outcome of the events. Tesleen and the Forgiven Dissonance fly off into the sky, heading to the direction of Lakeland.
Tesleen, the Forgiven is fought as the second boss of Holminster Switch.