In the quest Restoring the Cloth, you were asked by Mu “You have to give up your life in order to revive the Cloth. What would you choose?”. Answering any of the questions will lead you to the same scenario.
The answer to the question is Give up my life.
Answering this question correctly will skip a round of enemies.
The scenario for incorrect answer is you need to defeat the pax of enemies in order to survive and complete quest.
When you survive, you need to talk to Mu and from there the quest should now be completed. And Mu will repair the cloth.
Are you stuck on the same question in Saint Seiya Awakening Mobile? Let us know in the comment section!