I could only manage a sketch today. I ran out of time and energy.
X is another Hermit I don’t have a reference design for yet, but funny enough I have a lot of lore for the AU. I’ll probably post the lore when I have a proper reference done but X is one of the hermits that I’m really intimidated to design. I really love his videos and I want to do him justice. I’m not great with non-organic designs anyway and he’s full of armor.
So far, I like how this is turned out though. I’m going to try and finish it tomorrow, but I’ll have to come back to it if I can.
Just to inform the design, in this AU he’s obviously an alicorn. Basically a fallen God. Again, lore reasons. But the idea is that he’s a horse version of the Ursa Major and minors. There’s actually a horse constellation. So the idea is that he comes from this plane/dimension of star creatures. But after his twin brother tried to overstep his power causing the downfall of their kingdom. X Crashlanded in this little valley and started the “server”.
So his body is floaty like these Stardust creatures from the show, but also like the tantabus (which in this AU are creatures that can travel in between the two planes) I swear I have more more written. I’m just cutting it down for time and interest. 
When he fell out of his dimension his body was weak and not able to adapt to the new plane of existence therefore, he has his suit to help regulate functions like breathing. I always love the headcanons that X is a creature with God like eldritch powers, but he relies on his suit to exist in the overworld.
But yeah, that’s why his hair is all floaty and he’s gonna have stars if I can actually pull off drawing it -who knows.
Stay tuned if you wanna see it finished because I have no doubt I’ll finish it. I just don’t know when. Lol. I hope y’all like the design so far.