Seranni was a happy and compassionate young girl, who was beloved by everyone she came across. Seranni stood as a sharp contrast to her sister Velanna, who was her senior by two years. Velanna was a quiet, and awkward child, who lived as a social outcast among the clan.
Seranni who loved her sister greatly, made constant attempts to include Velanna whenever she played with friends, but every time Velanna faced rejection. Eventually Seranni could no longer convince her friends to play with Velanna, and her sister gave up on trying to make friends. Although the two sisters had little in common they continued to remain close throughout their childhood.
Seranni's clan came into conflict with humans living in the Arling of Amaranthine. Velanna wanted to fight them despite Keeper Ilshe's protests. Seranni went with Velanna when she set off with several other elves to seek revenge on the humans, hoping to change her sister's mind.She was kidnapped by the Architect during a raid on the Dalish encampment in the Wending Wood. The Elven Trinket belonged to her and was a gift from her and Velanna's mother.
Seranni is encountered during the main quest The Righteous Path.
The Warden-Commander first encounters Seranni personally in the Silverite Mine when she frees them from their cell. Seranni has become infected with the Darkspawn taint. Seranni has somehow obtained a key to the cell door which she gives to the Warden-Commander. The Warden can then persuade her to reveal more of the Architect's Lab and will gift a key to the Architect's chests. (Master Coercion is required). If Velanna is present, Seranni will tell her that she is fine, but that they need to get out before anyone else gets hurt. When questioned as to how she obtained the keys, Seranni evades the question and flees leaving Velanna and the Wardens behind as the darkspawn return.
If Velanna is present among the Grey Warden force at Drake's Fall during Depths of Depravity, Seranni will emerge from the shadows to speak with her sister. Seranni states that the Architect was good and tender with her and his quest is a noble one as he is trying to free the darkspawn and find a place for them; just as the Dalish are trying for. Seranni will then leave again without a trace.If Velanna survives the final battle and was not left behind at Vigil's Keep and allies with the Architect against The Mother, Velanna will remain with the Wardens, but years later, on an expedition in the Deep Roads, Velanna takes off on her own after saying she had seen Seranni in the shadows.