The Unending One represented both extreme danger and extreme benefit.
If Ves was able to harness the possibilities of the dark god's spiritual remnant, then he would no longer be as constrained by his existing energy limitations.
The insufficient supply of spiritual energy constantly hampered his work.
His mechs could be greater if they were able to fuel their spiritual abilities with an additional supply of energy.
He wouldn't be so hesitant about expending his own spiritual energy to perform various useful techniques if he obtained a replacement for his Grand Dynamo.
He might be able to help Gloriana, Ketis and other mech designers unlock their potential by flooding them with energy.
He could even elevate his prime mechs and future expert mechs by giving them the capability to generate spiritual energy independently, thereby lessening their reliance on mech pilots and design spirits!