After the invasion of the Elder Devil Realm, Three Kunwu Masters sealed a majority of the perfect devil Qi in areas of the Mortal Realm with the most abundant spiritual Qi, like Kunwu Mountain or the Myriad Depth Devilish Abyss in the Endless Sea. They used the pressure of these sites to suppress the corruptible Qi. Great Truths Sect was sent to the Heavenly South in order to watch over this ancient sealing formation.
After an Elder Devil Bloodflame escaped from Devilfall Valley, it slaughtered a few cultivation clans and sects that possessed devilish artifacts. The Elder Devil had arrived to the Myriad Depth Devilish Abyss in the Endless Seas. It destroyed the core of the grand formation, which was sealing devilish Qi. As result, the whirlpool appeared and it was releasing its spiritual Qi bit by bit weakening the formation.
The six Spirit Islands were distributed among the great sects from three superpwoers, the Righteous Dao Alliance, the Six Devil Dao Sects and the Nine Nations Union. The Spirit Turtle Island was gifted to the Drifting Cloud Sect for Han Li's efforts in suppressing the devilish Qi in grand formation.