The first batch of the Expedition Army that arrived, except for the logistics soldiers, were all strictly selected elites.
The Crystal Mage deeply understood that he was not suited for front-line combat, nor to become a leader. However, his long lifespan allowed his mind to store a lot of knowledge, and he could act as a "Mentor," which was what he had always been doing.
To establish an outpost and wait for General Lind's arrival.
But before that, they couldn't just do nothing. The Crystal Mage, who had once struggled at the Great Rift frontline, knew how to build an advantage as quickly as possible.