Suicide results when a human can no longer see a way out of the unbearable pain they're living in. Nex's biome was composed of struggle, difficulty, distress, and unbearable pain. Getting beaten up in a school bathroom is traumatic even to a person who lives in a generally supportive, healthy environment.
Add the physical and emotional trauma of assault to a biome of torment and pain, and from the perspective of the victim, any "way out" irises shut until light no longer penetrates.
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