When you fight carnage with venom at the end of the game when your in the last room you will see a statue of Rhino...throw objects like computers and large boxes at the glass to break it then throw carnage at the rhino it will take a lot of health off.

P.S. It might take a while but it should work !

To change your ultra mode,FOR TIGA/DYNA/COSMOS
Press either L2/R2
Tiga will change into red,blue,multi
Dyna will change into red,blue,multi
[Blue will have no special techniques]
Cosmos will be useless in his blue mode,he will be when he is in his second mode and first

How to Fight
First,Max your oppenent's damage meter, then press O,your opponent will feel drowsy, four buttons will appear[different characters have different amount of buttons] , square,triangle,circle,X
Press on any of these to execute the special techniques

How to Unlock Ultraman...
Justice
Complete The Cosmos VS Justice Storyplot With An A or S Grade
Legend
Complete The Cosmos VS Justice Storyplot With An S Grade
[Legend will only be available one the day you unlock him. Once you reset/shut down your system,Legend will be gone and you have to unlock him again]
Leo
Complete the first Leo storyplot
Comos Second Mode
Complete Cosmos VS Justice Storyplot

Unlock Kaiju/Seijins
Dinozaur
Complete Second Ultraman Storyplot with A or S Grade
Imit Dyna
Complete Dyna VS Dyna Storyplot with A/S Grade
Cosmos VS Justice Monster[I am not sure of his name]
I think for this one you must complete Cosmos VS Justice Storyplot also...i am not sure because I played this storyplot for a few times and then he was unlocked