Story

Herrscher of the Void
After a mental struggle with the Herrscher of the Void, Kiana drew upon the Authorities of Void and Fire to help her defeat the Herrscher and become the True Herrscher of the Void.
Herrscher of Dominance
To protect Bronya and Fu Hua, Kiana drew upon the authorities of the other Herrscher Cores she held, as a result she was able to make use of them and fight off the Herrscher of Dominance. Thanks to some support from the Authorities of Reason from a replica Core of Reason and Sentience through Feathers she was able to make full use of the Authorities she held and take on a new form known as the Herrscher of Flamescion, representing her new will to fight for all the is beautiful in the world. With her new weapon the Greatsword of Flamescion in hand she was able to defeat all the Herrschers of Dominance.
Kolosten
When she arrived in Kolosten Kiana planned to take on the Core of Dominance as another one of her Herrscher Cores. After obtaining the Core of Dominance it wasn't responding to outside input so Kiana and Bronya poured a steady stream of Herrscher energy into the Core to once again make it responsive, revealing that Otto had captured the Authority from within it. After a fight with Otto, Kiana was hit with the power of the Herrscher of Binding that had been summoned by Otto using an Imaginary Construct as the host, as a result most of her Herrscher power was sealed. Once the Authority of Binding was defeated Kiana regained some of her Herrscher power and strength. Following where Otto went Kiana and Durandal found the remnants of a rift he dues to get away, to open it again Kiana needed to use the Authority of the Void, however due to still having the affects of Binding she was unable to. Thanks to Mei providing help by connecting to the Core of the Void through the open space that the Will of the Honkai used to influence Herrschers, Kiana was able to break free from the Binding power and regain her power to open the rift. After a battle with Otto, Kiana inverted his power to swap the high values with low to defeat him, but it was apart of Otto's plan leading him to being more powerful than the Imaginary Tree and imprinting his will on it to create a new branch based on his past where Kallen would survive. After returning, the Authority of Dominance was returned to its Core so Kiana took on the Core of Dominance as another Herrscher Core like was planned.
The Moon
When Project Stigma was activated by Kevin all the Herrschers were sent to the Sea of Quanta and had mental seals put on their Herrscher Cores to prevent them from using much of their Authorities, due to having 4 Cores Kiana was able to stay decently strong. After meeting up with Bronya they fought through a bunch of Quantum Honkai Beasts which led them to Mei. Together they found their way to a bubble universe cut off when the Herrscher of Finality rolled the Previous Era universe back, which Kevin intended to use to hold them in to let Project Stigma complete. After meeting up with Senti and a version of Dr Mei, Kiana fought Senti to weaken the seal put on her Cores before using the Edge of Taixuan to focus and enhance the power to fix a broken bridge. After meeting up with Prometheus Mei helped Kiana face the seals and break them completely, returning Kiana to her full strength. The Herrschers then fought with an used an Imaginary Construct to relink the bubble universe to the Imaginary Tree where it merged with the regular one to return the group to the Moon to face Kevin. During the fight with Kevin Kiana was able to fight through his ice blocks through using the Authorities of Fire and Void, however it was not enough and they failed.
Project Stigma
When the group got back to Earth from the Moon Kiana helped in reversing the Imaginary Integration of Earth with Project Stigma through the use of her Void powers to renormalise areas and help travel around. While doing this Kiana with the help of Theresa and Durandal broke into the Kaslana Stigma Space and saved her father Siegfried. When the group broke into Planet Directory of Project Stigma Kiana followed to act as a portable exit point and to aid in fighting off the Imaginary Constructs. In the end Kiana linked with the Authorities to become an artificial Herrscher of Finality.
Herrscher of Finality
Once Kiana made the choice to become an artificial Herrscher of Finality she drew the Authorities from all the Cores with help of the Herrscher of Origin, through this she was able to get close enough to the Herrscher of Finality that the Cocoon of Finality granted her access to the Authority of Finality. Since she took on a new form the identity of the Herrscher of Flamescion was no more.