Seranni's clan was in conflict with Amarantine people. Velanna wanted to fight them despite Keeper Ilshe's protests. Seranni came with Velanna hoping to change her mind.
She was kidnapped by the Architect during a raid on the Dalish camp in the Wending Wood. Later she is found in the Silverite Mine with the complexion of a ghoul, but she acts quite normal, if a bit nervous.Furthermore, the Elven Trinket belonged to her.
During The Righteous Path the Warden-Commander is captured by The Architect and held in a cell. When the Warden wakes up, Seranni shows up and provides the key to the cell door. If Velanna is present, she will tell her that she is fine, but that they need to get out before anyone else gets hurt. However, Seranni dismisses her sister's warnings. If Velanna is not present, you can guess that she is Velanna's sister and may reveal to Seranni what became of her (however you cannot admit that you were the one who killed her).
Then, she notices that the darkspawn are coming to check on the prisoners and urges you to escape. The Warden can then persuade her to tell more of this place (Master Coercion skill is required) and she gives the key to the Architect's chests.
If Velanna is present at Drake's Fall during Depths of Depravity, Seranni will emerge from the shadows and a brief dialogue between her and her sister will occur. She will mention 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.If Velanna survives 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.
- Velanna will tell Nathaniel that Seranni used to put sap in her hair and pushed into an icy river twice.