They are experts on controlling ghosts and enslaving demons. They are also proficient in poisonous techniques and a few dark techniques. Although they are the weakest of the six sects, they are more powerful and wealthier than the strongest sect in the State of Yue, the Masked Moon Sect.
War with the Seven Sects of Yue
Ghost Spirit Sect sent their young Sect Master Wang Chan to the Yan Clan with proposition of their return to the sect 5 days before invasion of the State of Yue. They offered Thousand Spirit Sutras and a position of a deputy sect master in exchange for Yan Ruyan's marriage to Wang Chan and pair cultivation the Great Blood Spirit Art and a claim of the position of the Yan Clan Master for their offspring.
After betrayal of Spirit Beast Mountain, the Six Devil Dao Sects had great victory.
The State of Yue had fallen under the rule of the Ghost Spirit Sect. Their headquarters were at the previous location of the Masked Moon Sect. And the Tai Yue Mountains of Yellow Maple Valley had become the location of their side branch.
Cang Kun's Treasures
The Ghost Spirit Sect wanted to acquire Master Cang Kun's map and method to enter Devilfall Valley. When Marquis Nanlong was organizing a party to break into Cang Kun's cave residence, his friend Yun, who was low-profile Elder of the Ghost Spirit Sect, involved his sect into this. They paid a heavy price to bribe 3 early Nascent Soul stage cultivators, who joined the party. The Sect Master Wang Tiangu, Wang Chan and Yu Ruyan, joined the party too, but they didn't achieve anything.
After about 100 years, Moulan tribes launched an invasion. The final battle involved hundreds of thousands of cultivators. Long Han served as the commander of the Heavenly South Army and Divine Sage Zhu commanded the army of spell warrior. Ghost Spirit Sect was using Myriad Souls Formation and summoned the Bloodvile Ghost.  Before the culmination, Moulan received news about the attack of Soaring Tribes. Both sides stopped fighting and later agreed to unite against the common enemy.
After rumors began to spread that the Ghost Spirit Sect had acquired a method to enter Devilfall Valley, all other sects pressed them for information. The Ghost Spirit Sect was forced to allow other cultivators join them in that voyage. Expedition was led by Sect Master Wang Tiansheng, Wang Tiangu and Elder Zhong. They also reached a deal with Wei Wuya, enticing him with the Spirit Ether Garden, which was their primary objective. Additionally, they were looking for Spirit Kindle Fruits for Nature Origin Pills. Their venture was a failure. The fruits were seized by Han Li and Wang Ning beforehand. And the pocket dimension, assumed to be Spirit Ether Garden, turned out to be a tomb with the devil corpse. It all ended in a release of an Elder Devil Bloodflame out into the world. Elder Zhong had his Nascent Soul devoured. And Wang Tiansheng and Wang Tiangu perished in the spatial tear collapse.
Emergence of the Fourth Great Cultivator
Ghost Spirit Sect wasn't as powerful as it once was, after loss of Nascent Soul cultivators and a large number of Core Formation cultivators. The Spirit Controlling Sect, Devilflame Sect, and the newly-arisen Blood Slaughter Sect have joined forces to bring down the Ghost Spirit Sect. The Blood Slaughter Sect wanted to take the place of the Ghost Spirit Sect among the Six Devil Dao Sects.
About 130 years after the war against Moulan tribes, there was a grand marriage of Han Li and Nangong Wan. After the ceremony, Elders of the Ghost Spirit Sect visited Han Li beseeching him to help their sect. For their survival, they were willing to even vacate the State of Yue. Han Li agreed to help them with condition of Wang Chan's death. He alo received a Wood Spirit Gathering Bead.