Sorry if I am copying and pasting this from TA, but it's the only English guide really around for this game. Anyway, used Mu-12 and set it on Beginner difficulty, Astral Finish is D, D, D + X, use a taunt to get the meter, then do it round 1 to get away.. Then, plug away. Beware final boss's damage, it is quite heavy. He also regenerates meter, but I thought Haku-Men was worse with meter use. Rangey swords are nice!