Hi I got this one and and the others in easy mode and above by losing as little life as possible.
By finishing in "awake" mode with a flash final the 2nd round.
And by following the combat conditions like 60% of life remaining in the round, such character in the team, Finish the round in less than 50 seconds ect
I add what I marked for expert mode :
Hi, I had this realization earlier.
One thing to know is that you can get rank S on the same mission 10 times.
The simplest for me was the experience, this quest must be done several times to mount his characters of 70+ levels.
I managed to make the S fall by losing the least possible life
also finishing the 2nd round with a flash final in "awakening" mode
One way to reduce the life of the opponent is to start by typing with X and chain with a Kienzan or or meteor combination.
I used a lot of meteor combination.
Some I managed by doing a perfect in the first round.
use the support characters with LB (hold down).
Improve well your J-Skill use a G object. ( personally I always used the G-attack)
Also improve your support skills.
Stay a maximum on guard when your opponent can make his ultimate attack.
Avoid taking risks as long as he can do it.
In addition, do not smash from a certain level, the AI becomes very strong with the fast dodge, even if you make a quick dodge, they come to counter you.
Observe the weak points and how the opponent attacks.
For example Black beard his ultimate attack if you are a little away from him, the black thing on the ground will not affect you and you will not suffer any damage.
You can send him a Kenzan or recharge or recharge and call Sangoku to make a kamehameha while you recharge.
Some characters in higher difficulty are harder to fight as Cell Freezer Vegeta.
For example Cell does all the time explosive wave, Freezer him when he is the Ray of Death, Vegeta is the attack with lots of kikoha
(It seems to me that this attack that of Vegeta cancels the final Flash if it is done at the same time)
what you can do, too, is when you hit if your opponent is protecting himself, stop slightly and hit again.
If he does not defend himself anymore, you can perform 4-5 strokes and chase with a Kenzian or a Meteor Combination.