There are six secret realms in the cultivator's Yuan Shen and they could take the form of light wheels.

Secret Realm/Wheel




Wu Xing (Five elemental) Control of the five elements
Wan Xiang (Myriad) Augmentation of immense strength
Yin Yang (Yin Yang) Control of the Yin and Yang
Shen Cai (Life) Enhancement of life energy/life force/life essence
Dao Yi (Creation) Amalgamates the power of all the realms Head
Bloodline (Bloodline) Currently Sealed
Unknown seventh Unknown

If the cultivator has reverse-opened the secret realms, a Pangu God would emerge in the Dao Yi Secret Realm.