Mother Genome on Old Road 5 before recruiting Jadore as a character.
Characters
Complete the requirements after meeting Aria to unlock bonus characters from Spectral Souls.
Character
How to unlock
Hiro
Clear Old Road 4.
Rose
Clear Old Road 4.
Yunellia
Clear Old Road 4.
Normal Ending
Defeat Mother Genome after recruiting Jadore as a character OR defeat all human genomes followed by Edward without clearing the Abyssal Gate.
True Ending
Meet all requirements above, recruit all characters, defeat all human genomes and clear the Abyssal Gate BEFORE defeating Edward. Complete all remaining battles.