Augmentation

Augmentation is the ability to make the powers and abilities of oneself or another stronger. Augmentation has never been shown to be an active power, but merely a skill various beings learned after the exploration of the capabilities of their powers. Typically, when used between two parties, this power is only applicable if the receiving party is inferior in some way to the party responsible.

However, it is an extremely rare and powerful ability as it allows the user to makes their powers stronger and themselves more powerful. Witches have been known to use spells and potions to enchance their own magic.

Powers
Billie Jenkins learned to use her Projection power to enhance another person's power. She used this aspect only once, to strengthen her sister's pyrokinetic power, so that they could vanquish a demon thought impossible to be vanquished.

In 2000, Cole Turner as Belthazor hired the demon Andras to use the power of Anger Augmentation to make Prudence, Piper and Phoebe become enraged and turn on each other. This caused them to lose their powers and they had to get them back before Belthazor attacked and killed them.

The power of Empathy can and will automatically strengthen and evolve any other power the user possess if they cannot turn their empathic power off, since all magical powers are tied to emotions.

Prudence Halliwell, during her brief time as an empath, effectively had the entire rainbow of human emotions under her belt, and to extreme degrees. This exceedingly high inflow of emotion granted her a massive power boost, to the point where she became more powerful than the thought invincible demon, Vinceres.

Her telekinetic power was the first to advance, to a point where Vinceres, a demon who was immune to witchcraft, became vulnerable to it, and even allowed her to perform gravity-defying maneuvers so that she could meet Vinceres blow for blow in classic hand-to-hand combat. It also evolved her power of Astral Projection into Cloning.

The Power of Nine augments the powers of Prue Halliwell, Wyatt Halliwell, Chris Halliwell, Melinda Halliwell, Charlotte Halliwell, Cassandra Halliwell, Tamora Mitchell, Pandora Mitchell, and Henry Mitchell Junior; and they were able to vanquish the Mahon Demon using a white light that shot from there hands, even though Charlotte was infected with the ancient disease and not present with them at the time.

Environment
The ground containing the Nexus had the ability to enhance the powers of whoever lays claim on the ground, whether they be good or evil. For this reason, Warren witches claimed the house built on top of the Nexus after the 1906 Earthquake, and certain evil beings have attempted to take the Nexus for themselves.

Magical beings can enter and leave Limbo by using water as a portal. In Limbo, those with powers will find that their abilities have automatically increased in strength or have evolved into new abilities.

When Paige entered limbo her telekinetic-orbing power automatically advanced, allowing her to orb an object and her sister's soul, without calling for them. When Yen Lo, Phoebe and An Ling entered limbo their levitation power did not advance, but rather evolved into Flight.

Spell and Rituals
Prudence once casted a spell to triple a witch's strength in hopes of multiplying her telekinetic power.

The Source of All Evil once cast a spell to augment the warlock Hogan's power of Discord, turning all mortals in San Francisco against the Charmed Ones.

Potions
P. Russell once tripled the strength of her pyrokinetic power through the use of a potion made by the warlock Anton. The potion made her stronger and advanced her power into Fire Throwing, which she used to fight off her cousin's power of Cryokinesis.

Artifacts
Shuvanis and other beings in possession of The Evil Eye, an ancient Gypsy talisman that is blessed with the ability of augmentation, which they can use to augment their own abilities.

Lydia Nicolae owned the necklace and used it to augment her power of Optical Energy Blasts; the power to shoot green beams of energy at an opponent from the user's eyes.

In early 2002, Phoebe was experiencing problems with her powers, her power of Premonition was inactive and she could barely levitate. However, as soon as she touched the talisman, her powers became active once again, and even advanced allowing her to experience the event as she astral projects into her future self.

The swords of Wyatt Halliwell and Prue Halliwell: Excalibur and Hadhafang augment their fighting skills astonishingly. Especially when the pair were fighting Gadreel and getting him back to his cage.