Gu fusion

Gu Yue Bo teaches Fang Zheng that single refinement claims a Gu, while fusion is the more important craft on the refine side: through fusion, multiple Gu worms become one with a higher rank, called an evolution of life. ^{ch. 98} Broader refinement craft sits on refinement.

How fusion works

A recipe is required. Some Gu cannot be fused together; ancestors settled workable recipes through long trial and failure. Once the Gu already belong to the refiner, wild consciousness is gone and the refiner’s own consciousness sits on each worm. The core skill is parallel thinking: fusing those thoughts into one. ^{ch. 98}

In the clan-leader lesson, red steel primeval essence envelops the Gu in midair. As the consciousnesses fuse, the Gu circle closer; when the join holds, both erupt into linked light; the refiner must keep that fused state and throw primeval stones into the light until the higher Gu is complete. The stones become pure natural essence inside the light and leave only rock powder. Drop the fused consciousness and the light dies, the Gu fly apart, and the attempt fails. Too many failures can make both component Gu perish. ^{ch. 98}

Success rate rises with multitasking skill, deep understanding of the Gu used, and a correct or improved recipe. Even then there is no absolute guarantee. Fusing Gu is an evolution of life, a creation that condenses a long process into an instant. ^{ch. 99} Early-stage fusion is relatively easy; rank four and rank five success often fails to reach one in ten, and rank six success can sit near one percent, with each high-rank failure burning large resources. ^{ch. 121}

The new Gu usually takes one component’s ability and enhances it, dropping the other. White Jade Gu keeps and strengthens Jade Skin Gu’s defense and loses White Boar Gu’s strength gain. ^{ch. 105}

Boar line: White Jade Gu

Fang Yuan fuses White Boar Gu and Jade Skin Gu into rank two White Jade Gu. He maintains fused consciousness, feeds primeval stones into the light ball, then adds a wild boar king’s snowy tusk. The ordinary recipe of White Boar Gu plus Jade Skin Gu into White Jade Gu was long circulated, but adding that tusk was not; Fang Yuan knows from later-life knowledge that the tusk raises success rate about twenty percent. ^{ch. 99}

Liquor line: Four Flavours Liquor worm

Qing Shu offers a clan recipe that raises Liquor worm to rank two Moon Harbinger Gu, then rank three Seven Fragrances Liquor worm; only Seven Fragrances Liquor worm is said to refine primeval essence. Fang Yuan instead keeps the route that advances Liquor worm to rank two Four Flavours Liquor worm, then rank three Seven Fragrances Liquor worm, both of which keep the refining ability. That rank two fusion needs two Liquor worms and four wines of sour, sweet, bitter, and spicy flavors. ^{ch. 105}

Fang Yuan runs that fusion inside successive wine jars: redberry wine, golden honey wine, bitter shell wine, then white grains liquid, throwing primeval stones while holding the two Liquor worms’ consciousness fused. The result is the Four Flavours Liquor worm, which can refine rank two primeval essence up by a small realm. That run costs him over four hundred primeval stones. ^{ch. 121}

Failure cost

Failed fusion can injure the Gu or, by recipe, kill one of them. Fang Yuan loses a Little Light Gu when a Moonglow Gu attempt fails, while Moonlight Gu survives injured; he waits for recovery before trying again. ^{ch. 106} Materials and primeval stones spent on a failed run are gone. ^{ch. 121}