Why Kumoko stops using this particular skill later on?

Question

Kumoko-chan stops using

Parallel Will

During the fight with

the Arc Taratect army

In chapters

135 ~ 137

Why does she do so?

Answer 1

These are big spoilers, but if you don't mind them:

The Parallel Wills have separated from her main body and are each trying to take over the consciousness of the Queen Taratects. The Queens have a link with the lower ranked Taratects that can grant them control over the lower ones, Kumoko used this link to "upload" the Parallel Wills into the Queens and try to take control of them. It's proving quite difficult since the Queens are themselves being controlled by Ariel (Origin Taratect) through a similar link, one of the consciousness uploads itself into Ariel and tries to take over as well, which is how she finds out about Kumoko.