Angelic Buster customization works pretty much like any other character, or more like androids actually. You just get an extra window and I have images of that at the bottom of this post.
It’s almost like being two characters at once. You can have two different looks, woo!
How does one go about this customization? Well buy your NX/KK like you would normally, and buy your coupon(s) like you would normally and go use them silly!
FAQ
What can Angelic Buster look like with her default cosmetics?

Royal Hair & Face?
Yes, you can get them on BOTH modes of your Angelic Buster.
REG/VIP Hair Style/Color & Face Style?
Yes, you can get them on BOTH modes of your Angelic Buster.
All Stars Hair?
Probably, I will update when we get that event again!
Eye color? (Contact Lenses)
Yes, but only on non-transformed mode of Angelic Buster. If I can figure out how to do it in Dress-Up, I will update this area [: (Different colors are in the database, so it’s not impossible.)
What it will look like for Hair Style & Color for REG/VIP:

What it will look like for Face Style for REG/VIP:

I just wondered, when you view the hairstyles in-game, it doesn’t show the horns on the character. Would the horns be gone if you changed the hairstyle or is it only the preview that does not show them? Thanks :) Also very good job this site is awesome.
I think the horns are linked to the hairstyle. Whereas the wings and tail are linked to the character like with Kaiser. This is something I would have to verify first hand or find someone who has changed their Dress-Up mode hair though. I’ll comment back if what I find out is different than the above. (Thank you, I try to make it appealing to the eyes as often as I can~)
Okay thanks :)
hey, u know where 2 get the “Buster Face” and the “Intelligent Nova” faces?
I changed it and now i want it back :(
It may come back as a Royal Face just like Phantom and Mercedes did… That would be the only way to get them back though.