Arbiters (Will + Clarity) are beings seemingly made out of bright flames shaped into chain-link-like pieces. No matter what, they only do things by their own arbitrary whims and will not yield to anyone or most of the time even let anyone else influence them. When it comes down to it, every decision an Arbiter makes will be purely its own, and often decided completely ad hoc, as Arbiters tend not to care either way about anything. (They might have a few personal preferences, but not on anything relevant or important to anybody else if it doesn’t immediately concern them.)
Arbiters carry chains in their mouths to symbolise the idea that nobody else can control them because they are in full control of themselves. They can also lock one end of the chain around something else, gaining the ability to force it to do anything it can do consciously as long as it stays enchained. In return they become slightly more vulnerable to emotional influence from the enchained thing, though it still doesn’t have the power to force them to do anything.