Royal Guard, Royal Guard, and more Royal Guard will block everything.

Have you played DMC3?
DMC3 gameplay video Spoiler:
Don't watch it if you haven't played this game yet. There are some cutscenes that MIGHT spoil certain stuff for you. Just be warned.

Low Quality
http://babildo.brinkster.net/Videos/DMC3.zip

High Quality
http://babildo.brinkster.net/Videos/DMC.zip

A video I grabbed off gamefaqs board, by Panda Attack and hosted by dwarfkicker.
Pay extra attention to him just defending Beowulf's feather projectile, and Vergil's slash attack. He could do the "just defense" move in air, on ground any time. And it can block every single attack in the game. (Take a lot of practice with the timing in game...)