To every immortal, the most important thing is possessing Immortal Rings. No immortal with a sane mind would pass up the offer to obtain an immortal ring or form one.
It has four important uses.
If an immortal doesn't possess them, they will be stuck at the peak of the Real Immortal stage forever.
First, to go from Real Immortal to True Immortal, one must form or absorb an Immortal Ring. It is the only way to that one leap. Aside from it, there is no other way to take that step to the realm of true immortality.
However, if that isn't important enough, then having one's immortal core expand by tenfold is all the more reason to kill one's best friends just to form an Immortal Ring.
Once a warrior moves from the Empyrean stage to the immortal stage, their cores turn into an Immortal Core. To most, this core will be about a thousand times larger than when they were Empyreans.
