How would throwing some of the holy water on these creatures work?
Considering spraying some holy water on them or wait for someone to kill them and then help Vizeron-gollum...
(Identifying the creatures is a Hard (PPP) Knowledge (Forbidden) check if anyone wants to try. This would count as your action for this turn. Two boosts since you've seen them in action, setback for confusing conditions.)
As for the downed figure, that character is unconscious, but not in danger of expiring just yet, as far as you can tell.
You can certainly try a Medicine check, healing spell, or health elixir to see if that brings the Nemesis back to consciousness. But if the figure is undead, as some of you have suspected, standard healing won't help. If the creature is mortal, they will.
If you want to restrain the figure before doing any of this, that's an Easy (P) Coordination or Skulduggery check, since there won't be any resistance. (This also counts as your action for the turn.)