A Vampire's Guardian

Roman, is a young hybrid elf male, who was given a pocket watch to time travel as a gift. Once being sent back to the fictional late Victorian 19th century, Isle Silvercrest, he is assigned to protect Vin. Vin is a young vampire male, whose memories and abilities have been sealed. On his 18th birthday, he'd be killed by cultists! With only a year, can Roman protect Vin from his demise? Why is Vin being sought after? What is the REAL reason for Roman protecting him? WHO is behind all of this?