What can you do about emotional manipulators?
First, recognize that they exist. This contradicts our desire to believe that people are genuinely honest and not ruthless connivers.
Be aware of the tactics they use. Then, you have a better chance of not falling prey to them.
Find someone you trust at work to share your thoughts about what the person is doing. Often, they will also be aware of it and have their own stories. Then you won't feel like you are going crazy.
Be on your guard at all times when around a manipulator. You really can't trust them and should not reveal personal or confidential information. Yet, this is tricky since they are clever at getting you to trust them and open up to them. They will, however, use that information against you, possibly sharing it with others in the firm.
It is also critical to limit your interactions with them. They often like to stop by and share what they see as problems with other people's work (hoping you will agree). It is important to not get caught up in their conversations since they will use your comments when talking with others (e.g., "Bill said Karen's performance was really bad").
Trust your gut when dealing with an emotional manipulator. If it seems like they are lying, they probably are lying. Challenge lies and half-truths.
Don't let them guilt trip you. If they try this ("You don't care about all the work I am doing for you."), you could turn it back on them ("I do care, and now it seems like you don't appreciate how much I care").
Check or verify what they say with the original sources. They will often tell you what others have supposedly said.