There are a total of three endings available in the game, each with a trophy attached, which you can obtain in the following manner.
Normal Ending
As you finish the first portion of Chapter 11, you will be asked if you want to aid Metallia. If you choose the negative answer, and then continue to make that choice when prompted, you will be treated to a brief ending.
True Ending
If instead of declining Metallia your help, you agree that you plan to assist her, you'll proceed through the remainder of the chapter and then will receive the "True" ending.
Bad Ending
If before completing Chapter 11, you defeat three powerful optional bosses (located in the Ominous Cavity, Cicite: Reverse, and Old City Ruins maps), you will then access two final chapters loaded with content that leads to the final available ending.
To unlock all trophies, you will need to complete the game with each of the above endings. Nearly a quarter of the trophies available can only be acquired if you achieve the "Bad" ending.
