From the back cover:
A World of Dark Beauty... and Even Darker Perils
An evil tyrant and his mages create a tidal wave of destruction. Your party of heroes is the only hope.
Exotic Allies - Choose from a wild array of magical creatures with special abilities that fight and grow along with your party.
Greater Than the Sum of Their Weapons - Lead a varied and gifted band of up to 6 adventurers, or join your friends online for cooperative multiplayer games.
Devastating Powers - Turn the tide of battle with an earthshaking new level of skills--awesome character powers that will annihilate anything that stands in your way.
Rich Skill Trees - Enhance your party members through shared battles and prolific branches of advanced skill trees.