Aside from the body of the Piercing Blade Trick Spider, what Fang Mu valued most was the spider egg it produced upon death.
Once Fang Mu forms a contract with it using Covenant Blood Essence, he essentially gains a new entity akin to the Jeh ancient snake or the Three-Headed Crane Phoenix.
This is because the Piercing Blade Trick Spider possesses the ability to produce Child Spiders in large quantities, along with an exceptional web-weaving ability.
Fang Mu intended to exploit this ability to mass-produce Child Spiders.
Since these Child Spiders are connected by bloodline to the Spider Mother, regardless of distance, the Piercing Blade Trick Spider could perceive the condition of its offspring.
The Child Spiders produced by the Piercing Blade Trick Spider effectively became the best spies in the Giant Beast World, enabling Fang Mu to use the spider itself to monitor the surrounding environment.
