Book about supernatural beings collecting artifacts

This is a long shot here, I can't remember a ton but I think of this at odd times when I can't sleep.

I am pretty sure the main character was a werewolf. At some point they use a hydraulic claw to grab an artifact from someone who is possessed so it doesn't possess them. They had other artifacts sealed away to.

The only line I remember talks about how the possessed person was carrying the artifact sliver around in a bag, they look down and see blood on their shoe from where they killed their sibling for the artifact.

I thought the artifact was called a seru, but anytime I look that up I get references to a ps1 game.

It had to be from the 90s or early 2000s. I remember I was into a minor one at the time.