Gaal arrives at Synnax after 138 years of travel and awakens Salvor, who has been in cryogenic sleep for over 100 years after crashing into Synnax. To date, all human life on the planet appears to have been wiped out by the floods.
One of the most shocking moments in the series occurs when Brother Dawn is suddenly and swiftly executed by Demerzel, even as she comforts him by telling him she won’t let him get killed. His actions shocked even the Galactic Emperor and his elder clone, immediately ending their quarrel over whether Brother Dawn should be allowed to live or not.
We now see that his allegiance goes to the original Cleon. Therefore, Demerzel tends to support only perfect genetic copies of Cleon the First, and his ruthless slaughter of the genetically different brother Aurora proves it. Interestingly, it is then revealed that even Brother Day is not a pure genetic clone.
Which means Demerzel would be just as justified in killing him. The fact that we see Demerzel collapse and her human face ripped off also indicates that she knows the end is near and that she is in conflict with her identity as an ancient guardian of the Cleonic Empire.