Ness moveset with his own moves:
Standard Special: PK Flash-Same as Melee.
Side Special: PSI Hypnosis- Ness sends s psychic wave forward out of his head. if it hits an opponent, the opponent will fall asleep for a short time, which extends the more damage they have.
Up Special: PSI Teleport-In the air, it functions somewhat like PSI Teleport Beta, and you have to rapidly press B to make Ness Spin fast enough to Teleport. On the ground, it functions like PSI Teleport Alpha, and you run around and gradually built up speed. The move covers an incredible distance, and if an opponent contacts you while you are performing the move or if they're at the exact position where you come out of the Teleport, you'll explode and do damage to them. You can limit the distance by tilting the Control Stick less in the direction you want to travel.
Down Special: PSI Life Up-A chargeable move. For every full second the move is charged, Ness will recover 2% as he executes the move. The maximum charge time is 5 seconds. If he is hit during the charge, he will not recover any damage. When the move finally executes, there is a flash of light around Ness, and any character in the flash will also recover that amount of health, making it a risky move to use.
Final Smash: PK Rockin'- Ness stands with both hands clutching his head, his eyes closed, concentrating. He then opens his eyes and a flurry of psychic energy blasts out of his head in to his left and right. Anyone caught in the energy will be damaged immensely, but the move has absolutely no knockback. It simply holds them in place as it drills them with damage, and lets you pick off your weakened opponents afterwards.
That isn't "the issue", really. The problem is that you'll be taking a familiar character and completely changing everything people know about him. I'll admit that it's possible for Sakurai to change a character's special moves, heck, Sakurai changed Mario's Down Special already, however, I don't think changing a character's entire moveset is a viable option. Ness has been all but confirmed out, unfortunately.