To unlock the secondary form of all the characters, just beat the story mode. Then, in VS mode, push R1 to see the secondary form and select for it. This doesn't work on all the characters, only on the ones that have a secondary form in the anime (ie: Neji doesn't have one, but Choji does (his super pill form))
Naturally, this only works on characters that you've already unlocked (which should be all if you beat story mode)
Itachi Beat Itachi in Master (Story) Mode
Sasori Hiruko Beat Sasori in Master (Story) Mode
Chiyo Meet her Master (Story) Mode
Chiyo with Puppets Beat Sasori True Form in Master (Story) Mode with her
Orochimaru Beat Orochimaru in Master (Story) Mode
Kabuto Beat Kabuto in Master (Story) Mode
Sasuke Beat Sasuke in Master (Story) Mode
Kisame Beat Kisame in Master (Story) Mode
Yamato Beat Sai in Master (Story) Mode
Sai Beat Sai in Master (Story) Mode
Sasori True Form Beat Sasori True Form in Master (Story) Mode
Deidara Beat Deidara in Master (Story) Mode
In Player vs. Com, equip the ability "Night Phoenix," When the battle starts quickly double-jump into the air, and keep using it as if you equipped it. (Using either "Up, Up, O" or "Down, Down, O")
You need unlimited chakra activated, but the payoff is excellent. Also, the first time you perform this action, you might notice a small lag in framerate, however, every time afterwards will be smooth.
if you want to get him you need to get all characters exept yondaime (4th) and finished all the social, jutsu, special quests and then go to orochimaru hideout and at the first place in the first room you find him fight and win and you get him
This awesome combo can reduce large amount of health! And there is no way to escape from it!
Hanabi does an attack that is called "White explosive chakra palm" by pressing the direction of your opponent, O,O. This attack requires rolling. And if you have to do it again, you have to roll again, which is time consuming. Here is one way you can do that three times after rolling only once:
First, when your opponent is near a wall/corner, do the white explosive chakra palm attack. Just at the moment you hit your opponent bring your partner (R1) (It would work if you choose hinata as your partner. That is who I take. You can also choose neji). Also keep pressing 'O' while your partner is fighting until the three time white explosive palm finishes. Simple! Your opponent will get oppotunity to use substitution jutsu only while the first strike. If you hit him once, you can successfully do the other two.
I don't know why this happens... But, its an awesome combo! I hope i helped...