I got asked by @mxmia about my headcannon on Sindir and Avarin use of piercings and hair coloring etc so I hope this answer your question!
HAIR:
Coloring your hair as a Sindir is more of a choice whereas in some clans of the Avarin it´s a ritual they do each spring to show their gratitude for the returning wildlife and, both plants and animals.
Before the sun it was more of a prayer. If they returned from a long successful hunt, which can reach up to two to three months, they would thank whatever spirits they believed had helped them by "giving up their natural hair color" but also to look more spirit like to scare the evil creatures away.
So basically the best warriors have the brightest and most colorful hair. Although in the ages of the sun their best warrior still has colored hair.
Sindir does cut their hair when they lose in battle. They will cut their hair to shoulder length out of shame.
Avarins do not cut their hair only when they are children or if they are low ranked servants, there it´s shoulder length, for the servants, and the children it´s about three inches long but when they come of age (not adults) they stop cutting it.
MAKEUP:
Sindir only uses makeup if they are priests/monks, but they do love tattoos.
Avarins love makeup they usually like colorful eyeliner the most and all kinds of patterns. they also use mascara, even the children, it is only the ones of age that will use foundation and face paint.
In a rich Avarin household, with servants, the eyeliner can look different and the owner and their family of the house can use whatever pattern and color of eyeliner they want whereas the servant have a simple black winged look. (Edit: I draw Maeglin with bright eyeliner)
TATTOOS:
Both Sindir and Avarins use their tattoos to show their life stories, such as battles they have won, how big their family is, etc, although Sindir also uses them as decoration/makeup (like my Beleg design where he has tattooed a branch on his face) Avarins also use it to see who belongs to different tribes.
PIERCINGS:
Both Sindir and Avarins use piercings as decoration although Sindirs have a habit of attaching small hunt trophies to their piercings. They´re also more shameless about their piercings and more of them have their breast and lower parts pierced too where the Avain only have facial piercings, mostly ears, and only rarely their breast.
NAMES:
Sindir usually only have two names where all the grandparents deside one and the parents on another.
As at the Avarins it´s the person who has birthed the child can choose a name as soon as they want, the other parent has to wait till the child is about 10-15 years old so it matches there personality as much as possible, here the child can also begin "deciding" which way it wants to go in its craft, and when it´s 16-20 it begins learning it, this is also here where it is of age (of age in this tekst only means that it have decided on a craft and therefor also a "life")
...
My take on Eol is he is either a Avarin lord or a Maia of Aule and Namo who decided to join Melkor but got tired of it so he decided to live in a forest and completely ignored Melkor making it clear he isn´t working for any Valar or he made a Crowly (good omens)
