Your fighter's health bar is located at the top of the screen during battle between the character icons and the timer. This bar represents how much health your fighter on the battlefield has remaining, with the two smaller bars next to it representing the health of your other two fighters. If your fighter's health bar is green, they have yet to be Hit in battle. If it is yellow, this shows how much health they have remaining. During combos being done against your character, a portion of your health bar will turn red, showing how much damage is happening (being removed after the combo is finished). And lastly, if a portion of your health bar is shown in blue, this is how much health can be recovered by tagging in one of your teammates.