Zerginfestor
Learned
The safe way to fight Manus is to stand pretty far away, a few steps closer than the point your lock-on would drop IIRC. The fast Manus-goes-ape combo is no threat there and everything else is heavily telegraphed, and dodging several of the attacks causes him to leave his hand down and wide open for ages, long enough for shit like a jump attack with a Zwei. When he gets low enough to start doing dark magic you can either use the amulet or get a little closer to a sweet spot where you're not too close to dodge the dark shotgun attack and not too far that you can't sprint into Manus' crotch to evade the one where a bunch of dark bolts explode around you.
I see, good place for long range heavy weapons like the Demon Hammer, and Smough's Hammer, but I think Greataxe and fist users will still be in a world of hurt (though I'm capable of fast rolling with those bones on my hand, so it shouldn't be a problem for other users of the same type).