The Ferrymen

It came down to one necklace, one Ferryman, and one grief-struck villain hunting for revenge.
"The Ferrymen" is a tale of two worlds; Earth and Nikia, the realm of the Ferrymen and magic. We follow the OCD-diagnosed main character through his life-changing journey through both worlds- battling evil masterminds, learning combat skills, and fighting his own demons. Eli meets both friends and foes that he will never forget.

If you ever see the necklace, hide. It is made from a metallic thread of silver and holds a single diamond and immense, immeasurable power. I repeat, run and don't look back.

And, by Agis -- look for the mirrors.