The following art was created by @TDSpiral aka Garrett Post.
One can really appreciate the link from this to the Arbiter’s armor.
Here’s his more finished version:
This is really impressive. Given that the Arbiter in the Halo Escalation comic book series also wears a cape, this rendering captures the similarities between him and his lieutenants.
In case you haven’t seen him, here’s the Arbiter from that comic book series in his new armor. (Whether or not it’s just ceremonial is still up for debate, attempting to get an answer from 343)
So there are definitely some similarities.
Great work Garrett! I’d love to see your design become part of the official canon for Halo. be that in the comic books or a game.