Slow motion only when hit occurs.

Not an out of the box option for every single hit that I can think of, I could be wrong. But you can do a workaround if you only want it for specific moves. You could make it a throw move and transition to a hit confirm move or opponent override that had a slowdown built in it.

On second thought I think you can just transition to a different move (use the same animation but different ufe move file) in the transition options.