soulbound universe
you live in a society where soulmates exist 98% of the population can recieve their soulmates . 2% are with out they are called tarnished.
The mark consists of a half tattooed image which appears anywhere on their arms. the older soulmates recieves their mark on their 21st birthday at midnight.
Depending on their soulmates age of maturity , the older one will recieve their mark first. ( if he/she recieved their own at the age of 21 and his/her soulmate is 16 he/she will have to wait for their soulmate to reach a suitable age ). the soulmate mark starts as a very light grey colour and darkens into purple as the soulmate matures.
three strings will emerge from the bonding process . when a bonding ritual occurs the soulmates will see colour strings swirling around their glowing marks.