This can obviously be done through a number of ways: story plot, design, AI behaviour, weapons used and to name a few. But one that's been of particular interest to me is the use of language and voice.

Take Grunts for instance. In Halo 1 - ODST they spoke, taunted, screamed in English, and were overall pretty funny. I'd say it's not unreasonable to say that it was the comic relief they offered that made them one of the more memorable enemies in the series. Aside from bringing the lols, their humour made them fun to fight.

I'd say that the most interest enemies in Halo are the ones that communicate with the player, Grunts, Elites, Brutes and the Flood. While the Flood doesn't speak per se, their screams and roars are still damn well scary and achieve the desired effect.

Prometheans therefore serve as an exception that proves the rule in a sense. I doubt I'm alone in saying that the Prometheans were fairly uninspiring enemies to fight in Halo 4. Sure they had their share interesting behavioural traits, but despite Kiki Wolfkill's assurance that they wern't robots or monsters, they were essentially robot monsters.

They didn't have personalities. Grunts are cowards that make the player laugh. The Elites are proud warriors and battle field commanders. The Brutes are barbaric space apes who just want to rip you apart. And the Flood are gross, scary space zombies.

But the Prometheans? They're robot bullet sponges. We had no idea what they were feeling, why they were attacking us, or how are actions affected them. This lack of character seriously undermined any capacity for them to be interesting enemies to fight, let alone build a saga around. Sure 343i tells us they're "tortured human souls" but how is this conveyed to the player?

(The change from having the grunts and elites speak English was also a step backwards on the same principle)

What do you guys think?