Jace Lightwood is
Just like Will Herondale one of his relatives
Alec is his parabatai and his brother in all but blood
Clary once said "You're Jace Lightwood. You know that. Maybe you're a different person than you thought you were, But no one becomes a totally different person overnight. Just finding out that Stephen was your biological father isn't going to automatically make you love him. And you don't have to. Valentine wasn't your real father, but not because you don't have his blood in your veins. He wasn't your real father because he didn't act like a father. He didn't take care of you. It's always been the Lightwoods who have taken care of you. They're your family. Just like Mom and Luke are mine."
Enormous ego you really don't want to piss him off
Like a riddle, just when you think you finally work him out he changes
Is totally in love with Clary
Golden hair and brass eyes, he is described as angelic
He once thought he was Valentine Morgenstern's son
There is angel blood running through his veins just like there is demon blood running through Jonathon's veins
Wayland was also once thought to be his last name
One of the most annoying people ever according to Clary and a lot of other people
One of the best shadow hunters ever and the best his age
Demons, he eats them for breakfast