Fang Cang Lan did not declare herself as the Berserker Consort. When the Berserkers lost their Fourth God of Berserkers, some of the elderly who lived during the time when Su Ming was still around had decided unanimously that she was needed to placate the entire land of Berserkers.
The Berserkers could not be allowed to descend into chaos. Even though the Immortals were no longer around, the spread of the Dead Sea, the crumbling of the continents, the scattering of the islands that led to them to resemble the stars in a galaxy resulted in Berserkers severely lacking a power that could gather them together.
The islands were all independent forces. There was not a single spiritual symbol among them, and without it, they did not have hope for the future. It was especially so since the Fourth God of Berserkers had went missing. They had practically turned into a plate of scattered sand.