Could we get any additional information about this vorseal?

I believe we know that it increases the chance for NMs to spawn after killing an enemy. By additional information, I'm curious about the following:
  • Does it work like TH? Where the enemy is tagged with a debuff?
  • Does it count the player with the highest vlevel orseal that hits it?
  • Does the player with the highest level vorseal need to land the killing blow?
  • Does the action affect the chance? AKA killing with a weaponskill, vs auto-attack etc?