Mental manipulation is the act of when someone adds in foreign thoughts with the purpose of controlling your mind using mental/energetic abilities.
Getting rid of it can be frustrating while detecting it in the first place is annoying and chances are outside sources (Mental Scanners) will be the ones that detect it before you.
But moving on, how do you break it? Well it is relatively difficult but the concept is simple, you have to project to your MINDSCAPE (Theory Of The Mindscape/Soul Landscape) and then once you get there, begin to look around for any abnormalities.
In the end the abnormalities could just be something else, such as a natural seal, etc. BUT what you are looking for is a different in mental signature than you own, I don't expect you to immediately discover it, but expand your mental awareness through out it, and find it. Or you can follow the thoughts back to the source of where they are coming from.
Now that you are there, you can either. A: Destroy it using normal means B: Push it out and C: Simply stop it from functioning.
Destroying it normally mentally is a bit differnet, you can technically use a energetic attack, but it is best to instead use a mental attack to destroy it... Though moving on..
It is possible it could be a energetic construct causing it, instead of simply going to the mindscape instead looking around your surroundings for any constructs that you do not recognize, ALSO CHECK IN YOUR ENERGY SYSTEM! If thats the case, once you find it, destroy it normally.