Nine-tailed fox is the hardest boss for me. Avoiding the rocks and the random swipes, not to mention the ridiculous AOE hitboxes, is pretty challenging. And she can follow up combos with any number of attacks, so you have to be more cautious than I'd like. Staying mobile seems to help throw off the tracking on the swipes and rocks.
For the Toyotomi Hideyori fight, unfortunately tonfa was the only weapon that could keep him in a continuous combo after parry. Earlier in the Abyss or in the story mission I'm pretty sure other weapons could do this kind of long combo, too.
Song: Kiefer: AAAAA