Neri

Neri, the Spirit of Wisdom, is a blue fairy and a servant of the Ocean King in Phantom Hourglass. She joins Link after defeating Cyclok in the Temple of Wind, and is the second Fairy Spirit to add her power to his, after Leaf. When ten Wisdom Gems are offered at Spirit Island, Neri's power will half all damage Link takes, and the damage he takes will be cut down to a fourth when all twenty Wisdom Gems are gathered and offered. In addition, Link's shield can deflect stronger attacks with ten gems, but the shield's defenses don't seem to change after twenty are obtained. Link also has the ability to stun weak enemies by simply walking into them; this includes electrified ChuChus. With ten gems, a Phantom will only take 15 seconds of time from the Phantom Hourglass. However after twenty are obtained Neri gains a more subtle power, if Link is struck by a Phantom he will normally lose about half a minute worth of the Sands of Hours, at twenty gems Neri's new ability cuts the time lost down to five seconds.

Neri's name is slightly similar to Nayru, the Goddess of Wisdom. Her "blue fairy" appearance is somewhat similar to the first fairy companion who appeared in The Legend of Zelda series, Navi.

Trivia

 * As noted above, the name Neri is similar to Nayru, but she is most likely named after the Nereid sea nymphs of Greek mythology. This is fitting, since wisdom is commonly associated with the element of water.