Strong Supreme Soaring is is in fact a subtitle's translation for Dragon Emperor Supreme Flight. The Dragon Emperor will fly straight into the air to intercept it's opponent's special move, then crash the opposing bey into a wall.
Dragon Emperor Life Destructor is L-Drago Destructor's Ultimate and Final Special Move. L-Drago changes into Attack mode, then rushes at the opponent and becomes engulfed in flames. Then Dragon Emperor comes out from the flames and smashes with great strength. This move was first used to defeat Tsubasa and Earth Eagle 145WB in the Tower of Babel. Although, this special move failed against Nemesis, since L-Drago was not powerful enough resulting in a loss for Ryuga. This is probably Ryuga's strongest Special Move as he calls it the 'Ultimate Move'.