Actually my least favorite of the human helper trio or whatever they are called. Unlike my Uxie, mine is EV trained in Sp. Attack. Mine does however have low defense. It knows:
Psychic: STAB, good power, high accuracy, chance to lower Sp. Def.
Signal Beam: Decent power, chance to confuse, high accuracy, used to deal with Dark weakness.
Shadow Ball: Good power, high accuracy, decent chance to lower Sp. Def, deals with Ghost type weakness.
Charm: Used to compensate for my Mesprit's lower defensive stat. Also is good otherwise.