Quote Originally Posted by DarthEnderX View Post
I think it likely didn't pain him before because in the past, whenever the thing told him to run, he just did it.

This is the first time he REALLY tried to fight it. So when it tried to make him run, and he didn't, it started to cause him pain.
And it acted as a safety pin.

Killua not strong enough->escape
Killua strong enough to get rid of the pin->should be strong enough