How does the raised hand mess with an opponents chi, or psyche?

I don’t know about chi or psyche. I do know it is the perfect place to block an offensive blow in either direction.
There is a slight disadvantage. It can signal your “handedness”. You need to switch it up.

Parry move in martial arts!

See here.

This hand would mess with my psyche.

Fighting would mess with my chi or psyche even without the hand coming between us!!! ;}

“Chi attacks” are totally bogus in uncoreographed real world fighting – Whether they’re attempted by true Shaolin monks or martial arts wannabes, they fail on the street and can end in a total ass kicking or worse.

But as @LuckyGuy points out, it’s very different when you just hold your hands in an effective way to defend/counter punch against an opponent. Because nothing messes with your psyche like getting knocked out.

And this is what I’m talking about :

The MMA Fighter Exposing ‘Fake’ Kung Fu -
https://m.youtube.com/watch?v=uvq-2_5MdOs