They drop very useful abilities that allow you go much faster (for example, double jump and sprint). (cheatcc.com)
You'll start out a simple Freelancer who uses sword strikes to attack and can learn useful abilities such as Examine to learn about the monsters you face, but you'll soon be able to wield powerful elemental magic with the Wizard class (who, usefully, can cast defensive as well as offensive spells), or equip multiple weapons at once as a Charioteer (basically a horse - inspired warrior). (gamesradar.com)
They give your character very useful abilities like being able to instantly travel to any city you've previously visited, doubling your attack power in combat, replenishing your magic energy, and so on. (hardcoregaming101.net)