Beltran's protective amulet

Nobody knew Beltran wore anything until the day Aldo tried to take the Wraithblade off him with a grappling bolt from a rooftop across the town-hall square.

The shot was true. It went wide anyway, and for a moment it looked as though it had caught one of the balcony’s wooden railings, which had no business turning a bolt. Aldo, sharp-eyed and watching for the hit, caught the other thing that happened at the same instant: a small flash of light at Beltran’s neck, gone almost before it registered. Something under the collar had turned the bolt.

That single failed shot was most of what the party learned about how to kill him. Ranged work would not do it. He would have to be taken in close. The rest of that afternoon filled in the picture: a wordless stare that froze Aldo where he stood, and then Beltran stepping off the balcony and slowing his own fall, which told them he could be hurt and knew it.

Whether the amulet was ever taken off his body was never written down.