Water mage assassin.
The main protagonist was gifted in elemental manipulation. He was recruited at an young age to be trained in the water temple as a mage. However, when he returned to his village he found it in ruins. His house that he lived in with his mother was burned to the ground.
He saw an old looking chest in the rubble and found a fire-crested sword within. He set off on a journey to find out what had happened there.
I'm exploring what the character can do as in using the water elements to his advantage. I think it would be a pretty interesting concept to make him a silent killer because water seems harmless until you get swept into it's current.