We, humans, are actually very simple creatures. It is a wide known fact that we did not go far from apes – and I’m going to explore this fact in terms of World of Warcraft villains.
So, the baseline is simple: the best villain reflects our ape fears :) A most succesful setting utilizes them, and WoW is not an exception.
These fears – and villains – can easily be divided into very few groups.
Predators. We, humans, originate from herbivores, meat is not essential for our survival, and we genetically fear of anything primal with big predatory teeth and claws that indicates it could hunt us. In Warcraft and World of Warcraft this fear is exploited in Warcraft I, II (orcs, trolls, ogres), Mists of Pandaria (mogu, kor’kron and Garrosh), Warlords of Draenor (orcs, ogres).
Non-mammals. Insects, reptiles, fish and other sea life – everything most unlike us are often bad news: they stab and puncture, they can’t communicate with us – at all, they swarm, they own deadly poisons! And they aren’t cuddly under no circumstance, no sir! Aqir, mantid, saurok, predator fish, Old God tentacles – all fit. Dragons combine both predator and non-mammal danger.
Death. The mere thought of it scares us, and it was one of the major reasons why religions were born – to explain the unknown afterlife. Ergo, walking corpses and ghosts are scary as fuck. Warcraft III with its zombie apocalypse and Wrath of the Lich King, obviously.
Flesh Inside Out and Deformities. If you see open flesh, bones, deformed bodies, lack of or extra limbs – this is bad news. It looks, erm… unhealthy, and must be shunned, or else the whole tribe will get sick. Pulsing tumors, eyeballs, pus, visible veins or intestines, wrong number of limbs – a specialty of Old Gods’ theme, undead abominations, and also Starcraft’s Zerg.
Devils. This is quite new, and is a product of a Christian culture. We learned that a flaming humanoid with horns and hooves is evil and dangerous. Illidan, Sargeras, eredar and the Burning Legion as a whole, Xavius and satyrs are all here.
In the game itself we are experiencing an extreme pleasure if a villain/villains fall into one of the said archetypes – and most do, as well as combining them (“corrupted” orcs, deformed undead abominations etc). Just reminisce your feelings when a “predator” Iron Horde orc falls and is no longer “hunting” you. When “devils” of the Legion are incinerated by Vindicaar’s holy light. When you “clear” the corruption, and a tumor bursts, leaving the ground intact. When an undead crumbles and becomes what it should be: a dust under our feet. At the same time “normal” villains like Ashvane, Sylvanas, and mechanical/golem constructs don’t seem scary at all.
And maybe this is one of the reasons why Battle for Azeroth was not that inspiring to us? Yes, we had Old Gods (insects/flesh-out/deformity villains) and Nazjatar (fish/predator villains), but the major villain was War. We were basically fighting ourselves – and putting aside the thing that we perceived it meaningless lorewise, our primal backbone didn’t feel that as a threat to deal with immediately :)