Neri is the Spirit of Wisdom in Phantom Hourglass. She is a blue fairy who joins Link after he defeats Cyclok, the Boss of the Temple of Wind, which frees her from the seal that was placed on her. Neri's power is necessary to open a sealed door deep inside the Temple of the Ocean King, allowing Link access to the lower floors of the temple in search of clues as to the location of the third and final spirit.
Link can enhance Neri's power by collecting Wisdom Gems, which can be redeemed at the spring on Spirit Island. Doing so allows her to replace Ciela as an equippable ally, which increases the defensive capabilities of Link and his shield. Damage from enemies will be halved consecutively for each of the two upgrades Link has obtained, and he can stun many enemies by simply bumping them with his shield. Having Neri equipped also reduces the effects of Phantom attacks on the Phantom Hourglass, reducing the amount of time taken off from 30 to 15 seconds at 10 Spirit Gems and down to a meager 5 seconds when 20 have been obtained.