@azurrin what don't you understand, i might be able to help.
Aya is basically a pressurised vessel of chaos energy, that is about to crack due to the pressure getting to high for her fragile form, like a balloon filling with too much air, sooner or later she'll "pop" and die.
The solutions to the problem was either that they'd have to make Aya produce less chaos so that her vessel wont break or that she'd let off the pressure by using our protagonist.
That's why Narae react to the collar basically bottling up the chaos energy since would that not make the pressure higher?
There is of course the solution of making Aya's vessel fit the amount of chaos she produce too.
This is my read on the entire thing at the very least.