William was practically bulldozing his way through the Undead Army. Although they had the numbers, no single Undead among them could fight him head-on.
Although he suffered from several stab wounds, and other grievous injuries, all of them regenerated at a rapid rate thanks to the red mist.
The Vampiric Necromancer was a Prestige Class that was equivalent to a Vampire Prince. Meaning, it was one of the Higher Forms of the Undead class that was only lower than the Vampire King, which was equivalent to an Elder Bone Dragon.
The Death Knights and Dullahan were a tier lower than him, so they didn't pose any kind of threat to him whatsoever.
The only thing that could really threaten William on the battlefield were the Undead Dragons that were flying through the skies of the Black Tower. As long as those Dragons stayed where they were, William was like an adult fighting against tens of thousands of three-year old babies.
