Unlike the two first Bleach DS games, The 3rd Phantom is not a fighting game, but a turn-based tactic game. Two teams fight each others on an isometrically viewed battlefield in a style similar to the Final Fantasy Tactics and Fire Emblem games. When a character attacks an opponent, the screen switches to a side view, similar to the Bleach DS fighting games. If two teammates are near the same opponent, they can perform a tag team move more powerful than the basic ones which may make it easier to kill an enemy. This game also allows you to use kido and other special moves (e.g. Getsuga Tensho, Senkei and Tsugi no mai Hakuren). Once the player has won the battle, his characters will earn experience points which will increase their stats and unlock new abilities.
Source: Wikipedia, Bleach: The 3rd Phantom , available under the CC-BY-SA License.