So sorry that everybody is having problems. I guess that comes with the hitbox being invisible... I'll make it bigger. The jab hitbox was originally in the same place as before: at the tip of his palm where he used to stretch out his hand. I then moved it towards him and closer to the ground, to cover shorter opponents and to make it more jab-like. I'm pretty sure that if I make the hitbox a little bigger that will fix the problem, since I think it's in the right place right now.
@AFROofJUSTICE: I have had this problem before, but that's only when I have started changing stuff. He gets stuck in his idle animation for a little while, right? The only thing I can think of is this: On the ground his side-b has a new reflect hitbox that wasn't there before. I think that the idle animation comes because that hitbox is not there in the air command for his side-b. When you hit the ground the move switches from air to ground, keeping the animation in the same frame, but changing animations from the air animation to the ground animation. This also changes the moves, which normally wouldn't be an issue because they are the same in the ground and the air. Now, however, they are different, which might be causing the problem. I'll check it out.
I am currently away, but I will be back by Thursday, at which point I will be able to test both Dmickolas' soundbank and this current Mewtwo. In them meantime I have released one without the reflect hitbox, no permanent flame problems, and with a visual cue for the jab.
Sorry again.
Edit: It was a different problem. Side-b should work in the air now.