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The Blue Mandibles were a faction of Sangheili cannibals on the Refuge. They were named for the dark blue Sangheili blood that stained their mandibles. During a failure of the Refuge's irrigation systems on the eco level, the death of many vegetation, and the breakdown of the protein synthesizer, a group of Sangheili raiders led by a marauder infected with Blood Sickness began to eat others that they considered "lesser" Ussans. The Blue Mandibles had overrun parts of the Refuge's Section Two several years before 2552, until Bal'Tol 'Xellus led troops against them and slaughtered the faction. The Blue Mandibles remained as a very unpleasant memory for Bal'Tol.
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