Masters of Anima

If you did not get this on your first playthrough. You will need to load up the final battle with Zahr again via level select, and whittle down his health to around 10%. Stop your guardians from attacking to avoid killing Zahr and once his health is around 10%. Just use your melee combo attacks to finish off Zahr.

To be sure that this trophy pop, get the skill "Final Attack" of Otto from the Skill tree. However, when you carefully watch the video, Otto did not even use his Final Attack melee combo to kill of Zahr. As the trophy description mentioned use one of Otto's attacks to finish off Zahr. The video below shows how the trophy pop.