Originally Posted by
Hitei
The most powerful necromancer (the general sense of the word) is Arthas.
The most powerful Necromancer (the warcraft character type) is probably the former mage Kel'thuzad, followed by the most powerful of the Naxxramas necromancers, Gothik, Noth, and Heigan--and then lesser ones (Maleki, Gandling, Salramm, Rage, AU Ner'zhul, Dar'khan). You will notice these all share a lot in common (they are all casters, many of them are either Liches, or use the same set of iconic armor)
Much like Illidan and Arthas are two of the most powerful warriors (the general sense of the word) around, but neither is a Warrior (the warcraft character type) or by extension, the strongest Warrior.
I hope you aren't actually pretending Necromancers are cannon fodder. They make most DKs look like a joke.