Best level 6 unit.

Knights of Horror are the best! There's no competition. Maybe Nagas are close. They are cheaper than Knights, have MUCH more attack and defense, and are also faster, with 10 more health. The only downside is their damage. Dark Knight deals 15-30 damage, while Naga deals exactly 30. In terms of abilities: Nagas only have retaliation, while Knight of Horror has curse, unholy, and double strike (which is amazing with luck!). The choice is obvious...