According to the Spellbook of the Death, there are a total of five ranks of Undead Warrior that a Necromancer can create. From bottom to top, the list consists of Necros Soldier, Grave Skeletor, Death Knight, Undying Marauder, and Stalking Nightwraith.
The weakest being Necros Soldier, a simple animated corpse that is extremely easy to kill and has no special properties. However, they are undead and won't feel hurt or pain. Necros Soldiers can be very relentless in huge numbers.
Grave Skeletor retains most functions of the living and also enhances its agility greatly. A skeleton that moves as fast as a leopard and can rush at you on all fours like a demon from the underworld.
Death Knight is the strongest in the low-tier undead and requires an exceptional specimen in order to create. The corpse has to be in pristine condition, and Blaze would need to have collected more components for the spell in order to create the Death Knight.
