Remille travels to the Royal Palace in Denerim, presenting a group of Grey Wardens led by the Commander of the Grey of Orlais, Genevieve to King Maric Theirin and Teyrn Loghain Mac Tir. They mention that a Grey Warden who had knowledge of the location of the remaining Old Gods was captured by the darkspawn and thus Thedas possibly faced the threat of a new Blight. Throughout the conversation, Remille acts in a stressful manner and pleads the Fereldan lords to realize the urgency of the Grey Wardens' request.
Eventually, King Maric agrees to accompany the Grey Wardens in order to find the Ortan Thaig, but before that they have to first visit Kinloch Hold. There, in a ceremony in front of many Circle mages, Remille gives black brooches to the Grey Wardens which would allow them to not be sensed by the darkspawn and to King Maric some rare potions which would allow him to resist the darkspawn corruption. During the ceremony Duncan explores the rest of the tower eventually reaching the First Enchanter's room. He lockpicks a chest in his wardrobe and steals an ebony-black dagger. Genevieve eventually notices Duncan's disappearance and interrupts Remille's speech to go find him.
After King Maric along with Duncan and Fiona escape from Kul-Baras, they manage to make it to the surface. Soon afterwards, they are found by Remille accompanied by two other Circle mages. The moment they came close enough, the three mages cast a paralysis spell on all of them. Then they are taken to the Circle Tower where it is revealed that the Orlesians staged a coup and are now in charge of the tower. It is also revealed that Remille had allied with the Architect for some time now after they initially met in the Fade. He would help the Architect in its quest to spread the taint among the population of Thedas and in return he learned a large portion of the Architect's magic. Even the black brooches that the Grey Wardens were given before, had artifically progressed their taint as well as allowed the Architect to sense their presence. The conversation quickly ends when they learn that Teyrn Loghain is leading an attack to capture the Circle Tower. Remille orders the other Orlesian templars and mages to organize a defense while he remains with the Architect, the Grey Wardens and King Maric.After Bregan attacks the Architect, Remille betrays the Architect and attacks both of them. He mentions that he initially planned on making the enchantments which would be used to spread the taint in Orlais faulty, but he does not need to do that since he is already knowledgable about the Architect's magic as well as having the King of Ferelden in his custody. However, Duncan manages to release himself and Maric and Fiona as well. In the ensuing battle, Remille uses the black magic he recently learned. Because Remille was casting blight magic in addition to Remille's struggle with overpowering Fiona, his eyes turned pitch-black and inky liquid spilled from them like tears. Eventually the First Enchanter defeated Fiona and turned his attention to Duncan who used the ebony-black dagger that he stole from Remille's chest. The dagger managed to pierce through the magic and allowed Duncan to fatally injure the First Enchanter by stabbing him in the chest before he stumbled into Bregan who beheads him with his blade.