The system binding deities to sponsors and pilots; losing a sponsor mid-season frees a god entirely.
Eris's status readout spells the mechanic out: this deity has lost her sponsor and can no longer be sponsored this season, she is invulnerable on this floor, and she has been summoned by battlefield conditions with summoning rules applying. Her entry stresses how rare this is, since there has never been a single season of Faction Wars since the beginning where she was not sponsored by someone.
The practical effect is that Eris is no longer under the control of The War Mages, and her true personality and purpose can finally shine through. Carl could still hear traces of her dead pilot Hekla in her voice, but far fainter than before. Eris herself treated the freedom as license, calling it the most fun she had had since the initial purge.
The mechanic whose failure turns Eris into a free agent and a prime contender for the Ascendent Throne.