Use the Omphalos in your pack that Muto gave you. Once the magic power is released observe the changes in your body and the available quest list.

Show Quest Info

Introduction

Muto asks you to remember that after you have become a demigod you will be filled with a new and strange magic power. You won't know how to use it immediately. Fortunately Muto has experience with this change. The quest will automatically complete after one minute.

NPC Dialog

You'll feel a different chi inside yourself. After you
have adjusted to it your power will increase
dramatically. Don't worry if you can't control it the
first time, that's why I'm here to help. Relax, hold
onto the Omphalos. It represents the calm strength
of the earth. Now try to focus on your chi, feel how
your power is connected to the heavens and the
earth. Good, now slowly release your chi...