Brilluen along with Pennar and Marcan appear in the Taillteann Graveyard after the Milletian discovers a corpse with a glowing, golden aura. Brilluen mocks the Milletian for doing the Alban Knights' "dirty work", then suggests for the Milletian to inform the knights to come to the graveyard if they have an interest in what the Prophets are doing. Brilluen also tells the Milletian to scram. When Marcan and Pennar express interest in fighting the Milletian, however, Brilluen allows them the opportunity to do so. Suddenly, another voice in the graveyard is heard, causing Brilluen to question who is there. Once Avelin and Altam appear at the scene, Brilluen scoffs and the Prophets leave.
Much later, Brilluen and Pennar appear in the ruins of the Alban Knights. Brilluen teases Avelin, causing the latter to question how the Prophets were able to enter the area. Brilluen does not offer a satisfactory answer, however. The Prophets then engage in battle with Avelin, Altam, and the Milletian. Eventually, the Prophets escape.
Once the Alban Knights uncover the hidden Arthuan Altar in Lunae Valley, the Brilluen and Marcan appear, with Brilluen standing next to the now-opened chest containing the Arthun Shard. Brilluen teases the knights before an Apostle is unleashed. Brilluen then expresses disappointment, bidding the knights farewell as she and Marcan leave with the shard.
Brilluen and Pennar eventually arrive at Port Ceann when the knights discover the Heruin Altar. However, the Prophets find themselves caught in a trap set by Caswyn. Caswyn then taunts the Prophets, allowing Brilluen to realize what it feels like to be "treated like an idiot." Fortunately for Brilluen and Pennar, Marcan soon arrives and unleashes Zebach onto the knights. Brilluen gives him credit before the Prophets take their leave.
Sometime later, the Prophets appear at Port Ceann once more, but do not seem eager to fight. The knights hesitate, but quickly find themselves caught in a trap set by the Prophets. The Prophets are then able to retrieve the Heruin Shard and once again escape.
After Pihne becomes an Apostle, Brilluen thanks Caswyn for doing the hard work and further taunts him. She then leaves with the Apostle Pihne.
Eventually, Brilluen reveals that she had disguised herself as Avelin to fool the Milletian into coming to Lunae Valley with her. She tells the Milletian that she intends to get rid of them for good, sending Pennar after them as she leaves.
Much later, the Prophets are revealed to be within the ruins of the Alban Knights before the knights arrive. Brilluen points out that the knights underestimated the Prophets, then taunts the knights in her typical fashion. As the knights struggle to regain composure, Brilluen questions why they do not just join the Prophets, further claiming that Mother Ladeca did not abandon the world the way Aton Cimeni did. The Prophets then unleash Zebach onto the knights, this time in its final form.
After Zebach is defeated, the Prophets are found at the Avalon Gate by Talvish and the Milletian. Before Talvish and the Milletian can act, however, Brilluen casts a spell to temporarily immobilize them. The Prophets then raise the shards they successfully managed to steal from the Alban Knights to open the gate. Brilluen further points out that she enjoyed watching the knights' attempts to stop the Prophets before she and the others pass beyond the gate.
