Hair:
Ceria is your friend for length and color, you just need to actually have hair for her to color/style as well as credits, she has bills to pay after all.
Horns:
Minocharge/
Holstaria+Hornucopia for appearance and color/Lucifer if you only care about the Demonic flag.
Lips:
Lip Tease for color and the size, if the default isn't to your liking.
Skin: More Lucifer, alternatively
Pickmentation.
Eyes: Anything that gives you
vertically slit pupils and
Rainbow Gaze. If you want your sclera (whites of the eyes) to change color too, then your go-to is Lucifer again or
Dracoguard
Ears: Lucifer again, but if you get unlucky
Sylvanol(Franc) has you covered.
Arms:
Human arms and a bit of headcanon
or even more Lucifer if you want the Demonic flag specifically.
Breasts: Starting as either Half-Suula or Half-Gryvain gets you
very chesty out the gate. You can also just grow a pair regardless of race or gender with
several items but the simplest is
BoobSwell pads.
Tail:
Ruskvel nets you a tail that's basically a 1-to-1 appearance wise, if all the Raskvel busts are to be believed.
Legs: Go crazy, your guess is as good as mine what's in those boots. Human legs or our old friend Lucifer if you care about the flag.
Tone/Thickness:
You have options.
Clothes: Either
Dress Clothes or
Business clothes (and a little headcanon) for armor, if you want the gloves the
Knuckle Busters/
Custom Shock Gear have you somewhat covered for appearance (along with more headcanon), then just whatever ranged/shield/underwear and accessory you want.
You will have to do quite a bit of savescumming to get
exactly that appearance or you can bypass all mod work involved by using the
Save Editor to change your character's appearance but know the editor is severely outdated and that you
can break the save using it, so always make a back up before you go that route.
