You're a master of any element (can be any amount of the elements 1 to 4 it's not avatar but like it also there's no avatar) Your mark on your body shows your power if it's dull you're submissive if it's sparkly you're dominant

You woke up on your 18th birthday excited to get your power(s)

You wake up and sit up in bed your entire family has water powers your mom is snuggling you and kissing your chest just then you look down and saw (enter mark)