Alright, so.. I'm not the biggest fan of the facial structure that they gave the Fallen. Specifically when talking about the mouth and the fact that they seem to have left out the mandibles, which I find lazy of Bungie when it's literally canon that they have mandibles..

So, I decided to make my own slight revamp of what they look like under the helmet! Now keep in mind, this is purely fanart, not to mention only a sketch so far!

Here's what they look like ingame:

And this is my revamp:

To explain the hole underneath the ears and jaw, I like to think that they have secondary breathing holes on the neck that they can close through a muscle. The secondary breathing holes (one on each side) are to leave their mouths free when needing to eat, but so they still get their ether, thus they'd be wearing some type of ether distributing apparatus attached to their neck and secondary breathing holes. I can imagine this would be when they're aboard their ships, and out of their battle armor, again, purely fan idea.

The ears, I would say, is something they'd be able to wiggle around like they want to, the horns are purely aesthetic and look cool imo!

If anyone has any questions, I'll be happy to answer them!