First off you don't need a spell to awaken or use your inner power. Instead you can access it by meditating, visualizing, balancing and aligning your chakra, cleansing your aura etc. Once you open, balance, and align these centers of energy you can freely access you inner power with ease. Although I am not sure how you will manage it once you attain it as I am unclear of your purpose or intent, which may interfere with what I stated above. As Diana said, be more specific when asking questions especially ones that are so vague.
Blessings and Peace be with you,