There was simply no other way. He could only rely on the primordial spirit power of the Primordial Divine Ape, combined with the power of his own Blood Wheel, and perhaps he would successfully lock onto it.
As for the Primordial Divine Ape, he was certainly unwilling to agree.
The reason was very simple: the Primordial Divine Ape did not trust him and was not willing to hand over its own primordial spirit.
Chapter 1232