Is this all worded in the correct way?

Meanwhile, Tol and the Daltigoth soldiers continued their march north into Hylo along with Mandes, who agreed to help the Ergothians in their mission against the unknown force. When the Ergothians reached the seaport town of Old Port a few days later, Tol decided to enter the town in disguise along with the Dom-shu sisters, Mandes, and Darpo. The five discovered that the town was under blockade by the Tarsan navy and that Tylocost’s army was camped somewhere northeast of the town. On their journey out of Old Port, the group witnessed a Tarsan warship being destroyed by the gigantic insect monster known as XimXim. Tol and his companions determined that XimXim was the cause of the major defeat of Tylocost’s army and that the reasons for its attacks were that it must have felt threatened by the Tarsan forces in its territory.