Accelerate expansion and building an undead fortress

Alex entered the palace and found Xiao Mu and Xiao Hui there. She initially thought they were waiting for her, but it turned out they were just there for dinner.

"Miss Alex, how did things go?" Xiao Hui asked eagerly upon seeing Alex.

"Everything went smoothly," Alex replied with a smile.

Alex then flew to the top of the palace. In the twilight, the wind blew through her white hair, and her dress fluttered gently. She gazed out over the entire Undead City.

Outside the palace, there were a few houses and facilities, but not many. To Alex, the city felt too large for its current population. The areas near the city walls were mostly empty, with only a few undead stationed there, making the place look desolate. 

Undead City, where the dead outnumbered the living, felt more like a ghost town.

[Undead fortress construction materials: 100K units of wood, 200K units of stone, 50K magic crystals, 100K units of iron ingots, 100 Essence Shards.]