This works on PS3, don't know about 360. You create a fighter and all his attributed can reach max level! My guy's overall rating is 119! You can use him online aswell i think.
It's cheating but it's quite fun!
From Create A Fighter 1. Load fighter 2. Select fighter (press X) 3. Toggle stats on (press square) 4. Toggle stats off (press square) 5. Select fighter (press X) 6. Select customize fighter (press X) 7. Select fighter style/attributes (press X) 8. Select fighter skills (press X) 9. Now you have 3024 points to use to raise the skill level of your fighter 10. When you reach zero points (press X) to accept 11. Back out one screen (press O) and chose finish. 12. Repeat note: For this to work you must have a fighter to load. What I did was take the default guy and save him.