Sage

The Sage is the usual promotion of the Mage class in several Fire Emblem titles, and also the promotion of Shamans and Bards in Fire Emblem: Seisen no Keifu and Fire Emblem: Thracia 776, as well as an optional promotion of Monks and the Priests in Fire Emblem: The Sacred Stones.

Combat
In most Fire Emblem games sages can wield Staves in addition to Anima Magic, though in Fire Emblem: The Sacred Stones, Sages also gained the ability to wield Light Magic (They could also use Dark Magic due to a glitch you can abuse, giving them literally every kind of magic in the game at their disposal). It is interesting to note that in Fire Emblem: Path of Radiance, mages had the choice of either knives or staves upon promotion, with all Pre-Promoted sages having chosen the former. This marks the second occurrence of a magic-wielding class gaining a non-magical weapon upon promotion (the first being the Mage Knight of FE4, using swords), though the latter option is ostensibly more useful, in that it adds healing powers that draw upon the unit's magical power, whereas the former are not especially useful in the hands of sages, who will most often have low strength growths. Although it does offer a chance for a mage to attack units with high resistance with something other than magic.

In WiFi battles Sages are used mainly for their utility value. No sage is able to kill a combat unit one-on-one, as such they are mostly used for their staves. In particular, staves like Fortify and Warp provide a team with a large tactical advantage. The actual value of having a sage on a squad is debatable. Having a sage introduces a weakness onto a squad, in that the sage can be killed one-on-one, but cannot kill one-on-one back. Long range tomes like Swarm give the sage good finishing moves, and high versatility. The predominant reason sages appear on a squad is because they do not drain stat increasing items needed to make a squad of five powerful units. A team of four combat units and a sage will be able to distribute their limited boosts to the combat units, and give the sage only magic boosts. Where as a team of five combat units would need to spread the boosts thinner, and would have little need for magic boosts. The usefulness of sages depends greatly on the map. Map 6, for example, places great value in a sage, where as most other maps do not.

Variations
In Fire Emblem: Radiant Dawn, the Sage class is split into five different classes. Fire, Wind, and Thunder sages are able to use all three forms of anima magic, though their promoted forms are only able to acquire a ranking of SS in mastery with their preferred form of magic. Additionally, the Light Sage, a class exclusive to protagonist Micaiah, wields Light Magic and Staves. Meanwhile the Dark Sage Pelleas wields both Dark and Thunder magic.

Gaiden

 * Norma

Seisen no Keifu

 * Alvis - Duke of Velthomer and later Emperor of Grandbell
 * Sety - Levn & Ferry's son
 * Hawk - Sety's replacement.

Fūin no Tsurugi

 * Ohtz - boss of Chapter 14x
 * Brunya - one of Bern's three Wyvern Generals
 * Guinevere - Zephiel's younger, however illegitimate sister

Rekka no Ken

 * Aion - boss of Chapter 18x along with Kishuna
 * Ephidel - one of Nergal's morphs
 * Pent - Marquess Reglay, husband of Louise and father to Clarine and Klein
 * Sonia - one of Nergal's morphs who is the wife of Brendan Reed, but only married to gain control of the Black Fang
 * Limstella - allegedly Nergal's best morph

The Sacred Stones

 * Pablo - the leader of the revolt in Carcino and the boss of Chapter 10 in Eirika's route
 * Saleh - Ewan's magic teacher from Caer Pelyn

Path of Radiance

 * Calill
 * Bastian
 * Balmer
 * Kayachey
 * Heddwyn

Shadow Dragon
Note: Both were Bishops in the original
 * Wendell
 * Gotoh

Trivia

 * In Fire Emblem: Rekka no Ken, the morphs Sonia and Limstella, while formally classed as sages, have higher stat caps with respect to defense and resistance, both of which can reach a maximum of 30, compared with the usual 21 and 25, respectively, acquired by Nino, the only playable female sage acquired in the course of the game.

Sabio