Vaizards in Bleach
The Vaizards are a group of Shinigami that have obtained Hollow powers through "Hollowfication". In order to tap into their Hollow powers, they must don a Hollow-like mask. With this combination of Shinigami and Hollow abilities, they are very diverse in combat.
Vaizards on Legend of Bleach
Vaizard can be attained by undergoing experimentation through the forest. Currently there is an initial Vaizard stage and by training with other 'orginal' Vaizard, from the Bleach anime, will the player be able to progress in mastering and unlocking the true potential of their Vaizard abilities.
Vaizard, in LoB, has a high emphasis on those with the "Good" alignment, though it is possible for some exceptions.
Vaizards in LoB, can progressively become stronger depending on how or when they activate their abilities. A fully trained Vaizard will be able to unlock even more abilities to add to their repertoire that can easily change the flow of a battle.