Because undead creatures had just appeared, Dong Tianyu, who wanted to keep a low profile, couldn't purchase the corpses of undead creatures as he did at Saxon County Camp. It would definitely attract the attention of others, which didn't align with his character. Therefore, in order to speed up the upgrade of the Cave, Dong Tianyu had to personally go out to hunt those undead creatures.
Unlike their predecessors who would burrow underground to hibernate during the day, the undead creatures that emerged from the hexagonal prism portal could move about normally during daylight, seemingly unaffected by any need to burrow or similar skills.
Furthermore, these undead creatures encountered a Wizard Wraith right after they walked out of the portal.
The Wizard Wraith wasn't particularly perturbed by being suddenly transported to this plane since most of them, having been well-known mages before their transformation, paid little mind to the concept of traversal.
