Mage Class is fairly similar to a class in Final Fantasy or D&D. In this RP, Magic varies differently among individuals, and no to Magi have the same Magical abilities. For example, some Magi could excel at using Magic to heal an Allies Wounds, while another could cause mass destruction in the blink of an eye. So their often divided into classes to classify their abilities. Here are the possible classes for your characters.
Assault Class: Magi of the Assault Class excel at close range combat, and melee attacks. They can use magical weaponry, or magic to power up their own physical abilities. They often lack range, but they can still be a relentless force close range, and are very deadly if they are given the chance to steamroll their foes. They can endure physical and melee attacks fairly well, but their ability to endure magical attacks from Magi such as those from the Caster Class can be a little more damaging.
Caster Class: Magi of the Caster Class typically excel at long ranged magical abilities, and can use various types of magic to harass the foe from the distance. Their usually very agile and can endure a lot of magical attacks, but unfortunately, they have a hard time enduring Physical and Melee Attacks. Magi of the Caster Class are also capable of mild support abilities, but their no where near as strong the Support Class.
Shifter Class: Magi of the Shifter Class are typically can hold their own in all aspects, being able to use all forms of magic with the exception of Summoning, their versatility in battle is astounding, and they lack a lot of weak points like the other classes. However, at the cost of being Versatile, Shifter Class Magi don't really have any strong points either, their powers being out performed by the other classes perspectively.
Support Class: Magi of the Support Class don't actually excel at combat. Support Class Magi are better at healing their allies, along with providing their allies with buffs and dealing handicaps to their foes. Support Type Magi are also unique where they can provide useful abilities such as detecting objects and people, along with being able to analyze foes to detect a foe's weakness and weak points in their strategy. Unfortunately, despite their usefulness, Support Class Magi have a hard time in actual combat.
Summoner Class: Perhaps the most rare Magi Class, Summoner Magi can summon spirits to come to their aid, and help them in battle. However, they use weapons to fight alongside their summons, because without their summons, they have a hard time actually fighting on their own. Summoner Class are similar to the Caster Class where they often excel at speed, and being able to endure Magical attacks, but they are a little weak to Melee Attacks. Summoner Class Magi can acquire Guardian Spirits in a variety of ways, such as holding special ceremonies to summon spirits, forming contracts with living beings, or summoning the spirits of the dead. Summoner Magi also have different ways of summoning their Guardian Spirits. Some use physical mediums such as cards and keys, while others can conjure magic circles. It's also important to note that a Summoner Magi can only have one of their Guardian Spirits out at a time, and they can only collect 13 spirits total.