I vote that Blade is Kraus!
He is Kraus's likeness and his personality displayed in the other movies are very violent and merciless, much like Kraus. I refuse to believe that Blade is the jolly old doctor with a heart as big as Mianus. To me it just felt like the whole movie was building up the origin of Blade. Afterall Kraus didn't want to die, he had the spirit to go on fighting his side of the battle, even if he was infact evil.
The blade that we saw moving in the movie could possibly just be animated without a soul, kind of like how the sourceress in Retro Puppet Master made those wooden puppets move without souls.
An acknowledgable theory, don't ya think?