Here is an overview of each, via Bandai Namco America:
Claire is a qualified God Eater who specializes in logistical support and first aid.
A gigantic Aragami who uses his monstrous left hand to smash the player character.
A new action the player can perform that lets them rush towards an Aragami or make an urgent escape from impending doom.
Burst Art and Burst Art Effect
A special attack that players can perform while in Burst Mode. Burst Attacks can be customized into three attacks depending on the positioning of the player: on the ground, in the air, or while performing a quickstep maneuver. Each Burst Art can also be customized with a Burst Art Effect, which augments the Burst Art to the player’s preference. For example, add Rage Smash to a Burst Art attack to create an additional massive shock wave in front of the player.
View the screenshots at the gallery.