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When two Guardians, Eriana-3 and Eris Morn, triggered the perimeter alarms of Toland's hideout, Guren alerted his Lightbearer to their approach and asked permission to activate their defenses. Toland denied their request and noted they were coming for knowledge, not battle. Guren guessed they wished to know what he knew of the Hive, an assessment Toland agreed with and he declared that he intended to greet them with a smile and see how they might benefit from using them. Guren agreed with his plan, but suggested that he forego the smile as his unnerved other people instead of setting them at ease.
Guren and Toland joined Eriana, Eris, and three other Guardians on a mission to Luna in order to assassinate the Hive God Prince Crota, Son of Oryx. However, they secretly had no intention of seeing the mission through or faith in its odds of success and were instead intent on using the Deathsong of the Hive to transcend death. As Toland found Ir Yût, the Deathsinger and listened to her melody, Guren sent one final transmission mocking the followers of the Traveler and their previous attempts to stop his research, confident that Toland would succeed and reach new powers beyond death in the Ascendant realm. As they perished, Guren noted his only regret was being unable to live on to see Toland's final triumph.
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