"Flight to Salvation" - "The Veil is Torn" [Campaign 4, Mission 2]

There, before you can attack Claw with Biara, there will be four intermediate quests in four different parts of the map, separated by mountains. The space for the town will appear only during the beginning of the fourth quest. As soon as you exit the teleport into the Dark Elf territory, you need to deviate slightly to the left of the red tree observatory. There is a large, round area; this is the only place where you can place the town. The town will be almost fully built, except for the building for Titans, which you will have to construct. The town will be without troops, so it makes sense to enter the teleport closer to the end of the week to move the town, build the Titans, and buy some troops.
Don't forget to equip Wulstfren with artifacts for close combat before you finish the third mission. He will have a tough time.
Before storming Claw, visit all the morale boosters; Biara will have the Ring of Broken Spirit, which increases morale by 2.