What do the tattoos in the Eye's cult represent? (Vintage Eight headcanon)
When cultists reach a certain level of importance, ie, leadership roles, they get marks for different circumstances. Non-leaderly cultists get them as well, though it's slightly uncommon.
Rings on the arm represent the number of people that the wearer brought to the Eye's attention. Large rings usually symbolize 5 or, even 10 people, while smaller rings symbolise 1 person. Many cultists often enjoy flaunting the number of arm rings they have, as they feel that the more people they help enlighten, the more the Eye will appreciate them.
Eyes represent the number of reincarnations that a cultist has done. This is mostly to keep track of who has and who's yet to go through the process. The eyes are usually tattooed in sets of 2, though Prophet's a different case.
An eye on the chest symbolizes leadership. Said leadership can come in several different ways, whether it be the leader of a branch worshipping the Eye (ie, Callison and Brumfield), or being a or almost a cult leader (Ie, Prophet)
Markings near the eyes are mainly decorative, and have no major symbolism behind them. Though they CAN be a sign that a cultist has seen the Eye firsthand.
Although rings generally represent the number of people that a cultist has brought to the Eye, rings on the, well, ring finger, usually represent that the cultist has married another cultist. The marriage process itself is a can of worms I'll explain some other time. If someone has rings on the ring finger, but doesn't actually wear a ring, it can be a sign of divorce.
Not quite tattoo related, but the number of stars that someone wears around their neck represents two different things. If the stars are the same color, the number represents the number of kin that the cultist has, including themself (ie, Prophet having three stars for himself, Oracle, and Seer). If the stars are different colors, it's usually a representation of someone VERY close to you, usually a spouse, and the different colors represent the eye colors of yourself and the spouse (ie, Landon having a blue star for his eyes (excluding his red eye), and a red star for Prophet's eye.)
Aaaaaaand Prophet's top surgery scars are very self explanatory.