void SaveData() and TInstancedStruct<FNPCSoul> MakeDataForManagerSubsystem()

SaveData() is an interface function from the ISaveable interface. It is used by the SavingSubsystem to make all saveable objects start its saving logic. APooledCharacter uses it to make the struct that holds the data that needs to be saved and sends it to the SavingSubsystem for it to be saved.

MakeDataForManagerSubsystem() is the Blueprint Implemented (and Blueprint Callable) event that makes the struct that is saved by the SavingSubsystem. The blueprint children make the struct type that they need to save, then wrap it in an Instanced Struct so that different struct types can be saved under the same variable.