In Dragon Ball Z: Kakarot you can unlock the secret boss so you can have access to the alternate ending and a special reward, and in this guide we will tell you how to do it.
The first thing to do is to defeat all the evil enemies that you will unlock once the main story is complete. To locate them, simply open the world map and look for the red aura symbol.
Once identified you will have to beat them, and this will allow you to get a huge amount of experience points and Z spheres. Only then will you go to the village Lucca where they will be Gotenks e Vegito ready to challenge you: fight and defeat them.
Get busy and take your character's level to the max, as the final battle will be of very high difficulty.
Then go to the Kai's village to face the secret boss fight. You will find yourself against it Mira e Towa, the antagonists of the Xenoverse series.
Once beaten you will see the alternate ending and a special reward will be given to you.