Feng Jun's inspiration ultimately came from an iceberg, not the kind that describes women as cold, but an "iceberg tip" iceberg.
In other words, he can construct the Earth Vein underground, eventually revealing a tip, but it would emerge at Luohua Manor.
The part that emerges is, of course, a top-tier Earth Vein, as the Earth Spirit has said, able to facilitate Golden Core cultivation.
As for the external impacts of the top-tier Earth Vein, there are more mature solutions, and grading locks suffice.
If a top-tier Earth Vein truly forms, the spiritual energy throughout Luohua Manor could rival Kunhao Plane's — over time, it might even rival the Cultivation World of Kunhao.
Upon hearing his suggestion, the Earth Spirit was a bit happy; it could cultivate underground as long as it hadn't reached magma — "Such an Earth Vein can exist, but how large an area do you need?"
