Wei Wuxian feels like he's been kidnapped in his own palace. He trails after Lan Wangji, trying to keep up enough to not accidentally choke him too often, though he would think that something like that would convince Wangji to slow down.

"There is no sun. We're in the demon realm, don't you understand that? The food grows from demonic energy, which is residual in the ground, and things can be created with resentful energy, which is atmospheric and drips down from above. But there's no sun. No time."

His pet is very determined to give himself a tour, so Wei Wuxian follows along with him. It's not like Wangji can do any real damage here.