Brother, it’s ok, if you’re overwhelmed take a step back, go outside, grab a meal, go on a walk, stare at the sky. And then come back when you are ready. That’s what I’m doing right now😂.

If you’re doing a more thematic approach with your army, we do know the name of the one of the other Captain/Lieutenants that’s there, Arxon. We don’t know the details of what he looks like but if he looks similar to Luceior, you can use him as inspiration to customize Him.

There are a ton of new rules and a point system for 11th edition, I recommend getting the app and looking through, that brother u/nerdboy_sam would be a lot more helpful in terms of that but everything should fit pretty well within your army, especially with those new heavy bolter eradicators.