Hole Earth Gu

The Gu looks like a walnut with a wooden, uneven surface, and is as large as a watermelon. Activation needs at least a rank five peak stage Gu Master using all of that Master’s primeval essence. Once planted and fed, it cannot be moved; the link waits until the matching sub Gu is activated on the other side. Feeding costs two hundred thousand primeval stones each year, and each activation also spends a large amount of primeval stones. Ordinary Gu Masters rarely keep it alone; large sects, clans, and Gu Immortals with huge resources are the usual keepers. ^{ch. 424}

Hole Earth Gu’s range is limited to one region. From Hu Immortal blessed land in central continent it can connect anywhere in that continent, and is useless beyond it. ^{ch. 459}

Once planted in a blessed land, it can no longer be changed. ^{ch. 466}

Connecting Heaven Gu and Hole Earth Gu are only mortal Gu; blessed lands or grotto-heavens that use them silently spend heavenly power for the link. Setup needs consent from both sides so both apertures can spend that power; a secret plant without consent cannot connect. They also cannot work if set up outside in the five regions. ^{ch. 739}