Dragon Ball Z: Budokai: Tenkaichi 3's Ultimate Battle Mode has been extended from the last game. Here you will be able to play through different types of missions. In Sim Dragon mode, you will go through a series of simulated training sessions in order to increase your character's abilities. You will go through 10 days of training that will end with a fight. Across the 10 days, you can choose to train your abilities, explore the world, rest or take a senzu bean. While you don't do any physical actions (for the most part), you will have to manage your character's state. If you work your character too hard, the training will do no good and may actually remove skill points. While exploring, you will run into various characters and train with them. These trainings typically involve some sort of reflex mini-game.
Ultimate Battle also has a mode called Mission 100 that lets you choose a couple of characters and have you face off against particular combinations of opponents. From what I can tell in this preview build, this is going to be that really tough mode where you will spend a lot of time and make very little progress.
One of the features found in the Ultimate Battle Mode is Disc Fusion where the game asks you to pop in previous installments of Tenkaichi in order to unlock new modes. This is a nice feature that really encourages and supports long time fans of the game; after all, if there wasn't already enough incentive to get them to buy Tenkaichi 3, the ability to unlock modes with the previous discs might be the little extra push that's needed.