{based on an alt world I'm making.)
Phoenixes: These magnificent birds were often used for messengers. They are extremely fast and agile, with a few tricks up their wings. They can blind opponents with their solar glare and set fire to both enemies and encampments. They were also used to scout territories ahead of advancing armies.
Time Chargers: The last remnants of a once mighty race. They owe their lives to Celestia for taking them into her country and they will repay it. Armed with advanced weaponry ahead of its time, few can match their range and firepower. They are hit and run fighters and saboteurs. As well as being extremely clever, their regenerations abilities allow them to survive near lethal hits and get back into the fight.
Inquisitors: Inquisitors serve many roles. They are the moral officers of an army, tasked with boosting the moral of their troops and keeping them in line. Fervent in their devotion to Celestia, they follow without question. They are also master tacticians, scholars and the like. Their prowess with both holy sun magic and weapons is without compare.
Fire lizards: Large, fire breathing lizards. Bearing the colors of their habitat {black with red markings} these vicious beasts were tamed by Celestia herself. Their hardened skin makes them impervious to normal weaponry.
Priestess: Gentle and wise healers. They live their lives helping others and teaching them of Celestias ways. They wish the betterment of others and will take in enemy soldiers without hesitation. {As they believe that every life is sacred and that no one is irredeemable.} All Priestesses are adept healers, healing with both tonics and holy sun magic. While they are peaceful, they do also know quite a few defensive spells as well.
Knights: Celestias top fighting force. These imposing ponies are enhanced magically to be stronger, faster, and bigger than any normal mortal. Their thick golden armor is also magically enhanced and made from the strongest metals known to Equestria. {The armor covers them from head to toe, leaving nothing open to enemy strikes.} They are devoted to Celestia and Celestia alone and will fight to death for her.
Immortals: Humongous suits of armor. Each Immortal carries the soul a deceased Knight. {A Knights soul can only be transferred if the soul hasnt already been claimed by the Grim Reaper, meaning shortly before or after his death.} As it is a form of necromancy, they are not a wide spread phenomenon, except in dire cases. Even without their previous flesh and blood, the former Knights soul will fight on for the glory of both Equestria and Celestia.
-Evo