Tension Skills
In battle screenshots, you might have noticed a "skill" gauge below Elza's HP gauge. This gauge is actually referred to as a "Tension Gauge." It builds up based off your actions during battle. Once full, if you switch to command mode (which freezes time and allows you to select for command-based inputs), you'll have access to a special Tension Skill.
Spreading a Magic Circle with Wind.
Each character has unique Tension Skills. Famitsu introduce's one of Elza's, "Accelerate." When you use this, Elza's movement speed increases. This can be particularly useful when you consider that the battles are played in real time. You can make Elza use his wind magic to spread the Accelerate modifiers effects to other members of your party.
http://www.andriasang.com/e/blog/2010/12/27/last_story_preview/