Not connected story-wise to the previous two entries in the series, Untold Legends: Dark Kingdom was a game released in 2006, developed and published by Sony Computer Entertainment.
The game is a linear dungeon crawling action RPG. As the player levels up they get two attribute points to put into each level, and one spell point to spend on spells. Each class (The Warrior, Scout, and Wizard) has its own unique spells. The gameplay is similar, if not identical, to games such as Baldur's Gate and Champions of Norrath.