Yami is the final boss in the game, and damn he's (it's?) a doozy. REALLY long fight, including some very long cutscenes. But damn it, I love Yami as a boss (and the music is amazing).
Info: Yami has 5 stages. First one is a simple ball with saws and rockets, next is a segmented flaming, third is a slot machine, and fourth has swinging arms, legs, and guns. Look at the fifth for yourself. And seeing as there are so many attacks and variables, I can't really comment on strategy. It's an endurance match.
