Sky Strength Gu

Fang Yuan recalls it while looking at a rank five strength path borrow strength Gu sealed past the guest halt stele in Eighty-Eight True Yang Building. ^{ch. 560}

Pairing with borrow strength Gu

Borrow strength Gu cannot be used alone. Matched with Sky Strength Gu, it lets the Gu Master borrow the strength of the sky. The same pattern covers earth, fire, and water strength Gu for earth, fire, and water flow. ^{ch. 560}

Extinction

By that chapter Sky Strength Gu is already extinct. Earth strength Gu, fire strength Gu, water strength Gu, wind strength Gu, and similar Gu still circulate widely, though often away from that original borrow-strength pairing. ^{ch. 560}