To unlock this trophy you need finish all scenarios - including all alternative routes (stages) on the Custom Cast Mode.
This mode is more time consuming than Unicorn Mode due the difficulty on some battles.
Scenario1 have 3 stages to complete.
Scenario2 have 6 stages to complete.
Scenario3 have 6 stages to complete.
Scenario4 have 10 stages to complete.
Scenario5 have 10 stages to complete.
Scenario6 have 5 stages to complete.