Work around them whenever possible, keep interactions to a minimal. If there is a disagreement just try to cut off the confrontation and do your best to deal with the issues that ensue. Go over their heads whenever possible whenever issues do come up, and document any interaction you have with this person about sensitive matters, even if it’s unlikely something goes wrong, so long as there’s is a possibility, document it or at least have someone else to corroborate your story.
A narcissist loves themselves but is fueled by other people, working directly against them only gets them excited and makes them work back harder. Keep them out of your circle and don’t get sucked into theirs, and you won’t be drained by the social vampire.