You said the robots were made to fight?
maybe this one decided he/she/it didn't want to fight anymore and wanted to leave. (I am a pacifist!) Maybe it found TV and now knows that there is a bigger world out there than just "BattleBots".
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Two robots sitting in the robodome that study was talking about, while scientists look on...
"so, (telepathically) should we tell the humans how much we evolved" (check)...
"nah, F-Them! The're so stupid anyway and we don't need to get involved with their crap!" (checkmate)...
Start process over...
