It's strange, though. After all, Death Knights are undead, and this is stated in their characteristics; if you click on a unit, you'll see it. And for Markel, the specialization is to recruit all neutral Necropolis undead units. So why did they decide to exclude Black Knights from Markel's recruitment?
Well, surprisingly, 8 people joined in mission 4. They are undead, yes, but the description doesn't specify the castle they "belong" to, see:smile17:
