Ok so this may be spoilerish, so if you don’t want to see what it is then back out now, but this is from the trailer so I don’t really know if this is a spoiler… Also I am on a mobile so I won’t be able to provide the links.
Ok so during the recent trailer, we see the Arbiter killing what seems to be a storm faction elite. During Ign’s recent breakdown of the trailer, I saw what I believed to be the Arbiter killing Jul M’dama. So if you want to see for yourself, go onto their channel, watch the trailer, pause at 10:26 and look above the energy blade and you’ll see the same emblem that Jul has on his helmet. It may be hard to notice at first, but look real closely.