"sat on the bottom of the ocean, on a stern and stubborn rock. Your songs remind me of swimming, which I forgot when I started to sink" Swimming by -Florence + the machine
Stiles was born human
But not on land
Under the waves of the ocean with his mermaid mother
His mother quickly gave him away to his real Father who lived on land and was the Sheriff of a small town, she also gave him a bottle of magic lotion.
She told him to give him a bath in this once a year. It will keep his powers dormant and him safe from bad people who can detect him when he is using his powers.
He has powers such as manipulating water, telekinesis and whenever he touches water he grows a fish tail that replaces his legs.