Light Mage is Micaiah's class in Fire Emblem: Radiant Dawn; she is the only Light Mage in the game. It can be thought of as a female version of the Monk class from previous games. Micaiah promotes to Light Sage after being promoted to the captain of Daein's army at the end of Part 1 Endgame. Although this class cannot use Staves, Micaiah can still offer some healing assistance with her Sacrifice skill.
Being a magic user, Micaiah is at an advantage against several enemies, as a lot of early game enemies have low Resistance. Her unique spell, Thani, inflicts triple damage on armoured and cavalry units, but will be more potent against armoured units than the Rapier. However, there are a few issues with this class. Being a mage, it has low HP and Defense growths, ensuring Micaiah must be kept behind the front lines. In addition, her Speed growth is somewhat low, hindering a double attack. This is not always overcome on promotion, but neglecting use of the Light Mage hinders you, as Micaiah has forced promotions regardless of level. However, be assured that her Resistance, Luck and Magic are high, and her Skill is good.