i played yesterday, where all of the sudden
my racket is feeling soft
i get the feeling of softness when i hit the shuttle
but i checked my string, my stiffness of shaft
but somehow it just generates this sort of soft feeling
Plus, when i look at my racket, sometimes it became weird, like broken but not broken
(this is a mp99 2U user)

How can your racket and sometimes it looks weird?

Have a pro inspect your racket for damage.

From your description, it sounds like your racquet maybe warped. I agree with DinkAlot, have your racquet checked to be on the safe side.

How can your racket and sometimes it looks weird?

Have a pro inspect your racket for damage.

I would also like to have a pro who inspect my raquets...

hmm...what you mean by suddenly feels soft
maybe waldo98 is right your racket is out of shape