The Brood, an ancient race of dragons, is all but extinct. Their power was so strong that they had to be killed. A (as Ryu is named in this run), the last one of the Brood, is awakened after 400 years and decides he wants to know more about his people.
Well aware of his fearful power, A uses it until he becomes strong enough to rely on his physical power, after which he manipulates luck to an indecent extent, using frame-by-frame advancing to pulverize his foes and even the final boss. It may be a little anti-climactic, but it's much quicker this way.
This is currently the fifth longest published movie (Final Fantasy VIII is the longest RPG run). You might want to take your morning and your afternoon to watch this.