Gaea

Gaia was the Greek goddess of the Earth. She was one of the most powerful Gods.

In 2003 when the Titans were unleashed, the only known way to destroy them was to call upon the powers of the Greek gods. Leo Wyatt made the difficult decision to summon the powers and transfer them to the Charmed Ones. Piper Halliwell was gifted with the powers of Gaia, with her clothing transforming to fit a goddess. Paige was turned into Athena and Phoebe was turned into Aphrodite.

Leo turned Piper into Gaia because she'd always wanted as close to a normal family life as was possible for a Charmed One. She also had to keep Paige and Phoebe from getting carried away by their new powers.

The Charmed Ones managed to stop the Titans when Piper learned to control Gaia's powers. However, Piper was so distraught over Leo becoming an Elder and being forced to leave them that Gaia's powers briefly took her over. Leo managed to calm Piper down, and she relinquished Gaia's powers.