Survivial Trial needs these 2 functions... to allow you to better handle unfavorable outcomes in the survival trail, not just in losing, but in handling party damage. you wouldn't be able to go back to a previous one after you moved on to the next one, or after you collected your item prizes.
When you win a survival trial battle, you need a window reading:
"You are victorious, continue to next battle?"
"Yes (*on)" or "No, Reset Battle (*on)"
The "Yes" *on would save the battle state and progress as normal
The "No, Reset battle" *on would reset the current survival trial battle, and allow you to replay it
-AND-
When you are defeated on a survival trial battle, you need a window reading:
"You were defeated, do you wish to save battle state?"
"Yes(*on)" and "No Reset Battle (*on)"
The "Yes" would save the battle state, and all damage your opponent had incurred, as normal
"No" would reset the battle state, and your "in Battle" ninjas would be restored to their health starting the battle
These changes wouldn't be super huge, but they would make the survival trials a little more fair, and bring them more in line with the way that traditional RPG attrition challenges, like that would work...
-AND, One More thing-
Lastly... i think that there should be 1 "Recover" per play through of a survival trial, where you can click "recover" and each of your surviving ninjas will regain 25% of their maximum health...