I may have found something (EXTREME SPOILERS)

This is just an idea, but I think all of the arbiters has emotions. Well, let me correct that.

I believe each arbiter embodies a single emotion.

• Ginti is Impulse.
• Decim is Regret.

I can't pin-point any other arbiters, but I'm almost sure I'm right about this.

There's another point that might add to this. I believe that each arbiter embodies these "Advanced" emotions that aren't just happy, sad, angry, etc. for a reason.

Think of every soul Decim judges. If you've guessed what I'm getting at, good.

Every single one has some regret.

The same goes for Ginti and his souls. The only two we see him judging met their death due to being impulsive.

Also, Ginti being the embodiment of human impulses explains why he was so quick to send Mayu to the void.

Last point, and this one's a bit of a stretch:

What if the arbiters (Who we know are souls fished out of the void) are people who died to that same emotion? We're told the void only lets you feel the most negative of emotions, so what if they are human souls that have been broken down to only feel whatever emotion lead to their death?

Someone tell me if I'm wrong here, because I've really got this thought out.