Lucario attacking Skyworld with his Final Smash
Aura Storm, Lucario's Final Smash, consists of a large beam that deals large amounts of damage and then finishes with a large hit at the end. The more damage Lucario has, the longer this Final Smash lasts. You can also change the angle of the beam by moving the analog stick left or right. You ,however, avoid this Final Smash by jumping over Lucario, but such a feat is quite difficult for most stages and/or characters.
Aura Storm was designed specifically for Brawl, having no basis in the Pokemon canon.
You can obtain a trophy of this Final Smash by completing All-Star Mode with Lucario.