Lucifer was afraid that those tunnels would be permanent, just like a scar on someone's skin.
If the tunnels were really like a scar and couldn't be removed, he doubted whether Raguel could close down the domain peacefully or not.
Raguel tried hard to recall all things about the domain and immediately nodded his head, trying to reassure Lucifer.
"Let's put aside our grievances first. I'll be honest with you, and you have to believe me."
Raguel said a few more lines to make sure that the demon lords would not kill him before he revealed some information about the domain.
"I need around fifteen minutes to fix the domain until it can be closed manually, but those tunnels are indeed hard to close down..."
And the tunnels did prevent Raguel from closing down the domain, which was why those tunnels that suddenly appeared like spiral wormholes were so annoying.