I watched, the other night, someone speed run through Unlimited Saga.
While the game was in Japanese, I could basically tell their tactics. First of all, they avoided almost all battles. Secondly, they got skills that seemed to emphasize speed. Finally, they used two main tactics – knife skills with a high chance of a deadly strike, and a specific axe technique which tends to kill the final boss quickly. The player finished the game in about an hour and a half.