In Dragon Ball Z Kakarot you can unlock and defeat secret boss Mira. In order to complete the game with 100% you also have to kill this boss, which will also unlock the following trophy:
You can find more solutions and tips in our trophy guide.
Unlock and Defeat Mira
To unlock Mira , you must first defeat all Villainous parties in the game. They are marked on the map by a red crown symbol.
Once all Villainous parties are defeated, Mira can be found on the planet "Land of the Kais" (press TRIANGLE on the world map to see other planets). He is a level 100 enemy and has a lot of health.
To defeat Mira, you should pack some items to heal. In addition, you should have two other characters in the team who support you. Try to use the Saiyan 3 transformation as much as possible, you will do more damage.