Simon:

Simon is Clary's bestfriend and has been for many years. He is a normal human that got caught up in the Shadow World... and ends up part of it. Simon gets changed into a vampire after getting kidnapped. Though he is a Downworlder, he likes to help the Shadowhunters. After getting Changed, he drinks some of Jace's blood and that makes him a 'Daywalker' meaning that unlike normal vampires he can go outside during the day. He even stays to live with his mother, but eventually has to leave after her finding blood. He ends up living with a werewolf that was sent to watch him.