They are slowly building their foundation for conquering this world slowly, as long as they could occupy this city with their believers, they could spread their faith to other cities, the more villages, towns and cities they occupy, the greater the number of believers they will have.
They wouldn't force anyone to believe in their religion but they'll eliminate those that threatens their group, Don² have already deciced to increase the influence of their so called sect, as long as they have an equal amount of prestige as the local great sects.
They'll be able to participate more on this world's politics, Qi Nulong have already shown that there are some special clans that have unique abilities, as otherworlders, they wouldn't be able to move efficiently but if they could raise some powerful or intelligent subordinates, they'll be able to solve this problem.