Black Magic
There are four tiers of increasingly powerful black magics. Black magic consists of damage dealing elemental spells along with debilitating status effect spells. The best way to develop these spells is through Jansen, who eventually masters every tier of these attacks.
White Magic
White magic includes healing, restorative and protective magic that keep your party's health up. Keeping a white mage with your party is a near necessity for most areas in the game and pretty much every boss will require at least one dedicated healer. There are seven tiers of increasingly potent spells. Early on Jansen is your only source of healing magic, but his natural white magic limit is tier 3. Cooke is the dedicate white mage and therefore your best source for advancing your party's skill in this vital spell set.
Spirit Magic
Spirit Magic is a mix of both colored magics. Some spirit spells empower or heal your party members while others damage or disrupt your enemies. Spirit magic provides five tiers of spells that support both your fighters and your healers. Having a strong spirit mage can make your party more flexible against even the toughest enemies. Mack is the only spirit mage you can recruit and without his development you cannot take advantage of these useful powers.
Command skills
Command skills are warrior abilities that add a buff to a basic attack. There are a variety of different command skills that can be learned from both mortal party members and from equipment. Most of the basic command skills that add more damage to an attack are learned from Mack. Most passive commands that help flee, steal, evade enemies or provide some other indirect support are learned from Sed. Finally, skills that improve attack based on the party's current situation or skills that circumvent enemy buffs are learned from Tolten.
Passive Skills
Passive skills are abilities that aren't activated in combat but offer a constant advantage to party members. Immunities to certain status effects, defensive boosts against certain elements or increased attributes may all be considered passive abilities. Immortals learn these mostly from equipment while mortals will occasionally gain passive skills that boost their natural abilities.