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During the early days of The Last City, Callisto defended the City against a massive assault of Fallen. She was among the many Titans who participated in miles long charges to reclaim territory from the invaders and push them away from the walls of the Last City.
The Red War
When the Cabal's Red Legion assaulted the Last City, Yin was one of the few members of the Firebreak Order present in the City and attempted to fight the Cabal alongside her fellow Guardians. However, their Light was taken from them when the Red Legion attached a device to the Traveler. As she fled the occupied City, Yin saved the Firebreak Order's eternally burning Fire Victorious from Firebreak Plaza by carrying it on her burning mark.
After the City was reclaimed from the Red Legion, Yin was asked to appear before the Consensus. Commander Zavala thanked her for saving the Fire Victorious, but Yin stated that any member of the Firebreak Order would have done the same. Executor Hideo informed her that repairs to Firebreak Plaza were nearly complete and that they could hold a relighting ceremony for the Fire Victorious next week. Yin declined, and informed the Consensus that she and her fellow Firebreak Titans had decided that keeping the Fire Victorious in the Last City was not enough. Each member of the Order now carried embers of the Fire in their Ghost's shells, so that Wei Ning's fire could be spread to every battlefield they fought on.
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