What is more terrifying?

Artes as undead is just a puppet of Ner'zhul, and nothing more. He wasn't pursuing anything on his own; Ner'zhul was leading him to free himself. Artes ceased to be just a tool only when he merged with Ner'zhul.

Oh, of course, that's how it is) But since the blade imposed its will on him, what did Arthas essentially become? Wasn't he an embodiment of will?) And isn't it the blade's will that then has "mind and meaning"? :)
2+2=4+0)
I may not have studied the entire history of Warcraft thoroughly, except for reading excerpts from books, but I remember that his charisma didn't disappear with the acquisition of the blade, except that it moved in a dark direction)
If he is so "stupid and meaningless," then why is he needed? If there wasn't this "stupid and meaningless" death knight, Ner'zhul would still be sitting somewhere.
:p

I hasten to disappoint you: most often, dragons are greedy and cruel bastards who sometimes also strive to become dracoliches and gain immortality along with unlimited power.

All the dragons I've seen are good and fluffy. They just don't like uninvited guests. Of course, when brave knights in crowds rush into a cave with the aim of cutting the dragon into pieces and taking its treasures, it should sing songs of happiness and, dancing, offer its head to the sword :)
And regarding those who crave to transform into dracoliches... I haven't seen any. Even a couple of dracoliches, not deprived of will and soul, committed all their evil deeds only to regain their true essence.

in any case, a demon can not only kill everyone, like some random lich, but also convert a fool into its faith. in the end, I have not had to eradicate sects that worship the undead.
that is why a demon is much more dangerous and terrible than a corpse) a demon cannot be killed (=
he will only "go back to hell" in most cases. but if you cut off the head of a zombie or vampire, that's it.

The undead also very persistently converts people to their faith;)
If you cut off a zombie's head, it is unlikely to harm it in any way...
And a vampire can be easily resurrected.