Ninja Gaiden Sigma 2

You can only perform Ultimate Ninpo in team missions. Both you and your partner need to cast a Ninpo spell together to turn it into an Ultimate Ninpo. When playing with the offline A.I it will automatically join your Ninpo and perform an Ultimate Ninpo, therefore, it is easy to grind this offline too. However, this is completely unnecessary if you are aiming for clearing all team missions, as you will more than likely perform 100 Ultimate Ninpos on the way.