Please help me…
I had a gallade that know hypnosis and false swipe to catch other pokemon. One time I change his moveset to support my Elite 4 battle (because his skill is one of the best in my team) and now I cant re-teach him Hypnosis using move relearner in the secret base. Is that move lost forever and I must raised another kirlia to have Hypnosis? 
You’ll have to raise another.
Do your Gallade at its max level?