Heros of Arcadia(Trollhunter x male autistic reader)

In arcadia there live two young boys named James Dulac Jr. and Y/n L/n. Jim dad is gone when he was young and Y/n parents died when he was only 1 year old making Barbara Jim's mom take him under her care and adopt him. Despite the fact that Y/n parents died he have a girlfriend that help him trought the hard times named Claire Nuñez who love him with all her heart. One day under the bridge of Arcadia two trolls fight under the bridge and one was killed and falled down the bridge. Jimmy found the amulet the troll possesed and the amulet told him he was choosed by it to become the new troll hunter. Later at night as Y/n was driving trought the night with his bike a mysterious figure stopped you and spoke to you. He then gave you and orb revealing a watch that attacked to your wrist. what happen next? find out