Are these sentences worded in the best way?

FYI- Szass Tam is the lich/ undead wizard. Around a week later, Hezass Nymar magically traveled to Eltabbar, the capital city of Thay, and met with the Council of Zulkirs, several of the tharchions and military officers loyal to them, and Iphegor Nath, the High Flamelord of the church of Kossuth. Hezass revealed to the assembly that he wanted to switch sides and that Szass Tam was going to soon besiege the Keep of Sorrows. Seeing this as an opportunity to decisively defeat the lich, the mage-lords immediately decided to gather the bulk of their forces and confront the undead wizard’s legions when they attacked the fortress.