I would like to see more enemies like the Gerudo from Ocarina of Time. Link almost always fights with creatures or big, hulking, armoured monstrosities. Giving him a quick, nimble foe who can match his ability with a sword and perhaps other weapons, maybe even has some fancy equipment of their own, would make for some interesting fights I think.
As an example, imagine an enemy that had a clawshot and used it to yank the sword out of your hands and then immediately went on the offensive. It would force you to be more defensive or imaginative with your approach. Would you immediately try to get your sword back or use a different weapon? What if the foe started using your sword against you? An enemy whose actions are a little unpredictable and who has the ability to present a real challenge in this way would be great I think.
It's interesting that you say this because I actually formulated a villain who served as this exact antithesis to Link. Essentially, he is Link's rival and there's this innate corruption of his soul over the course of the game. Which I thought would be a fresh take on a villain, where Link and the villain are hold a relatively close relation, but their destinies take them down two different paths. It'd be a good way to show something, no matter how inhuman he may become, with very human qualities. Anyway, he is the Prince of an adjacent kingdom to Hyrule, Ordon (for the sake of a new story), and is bent on being the best to be fit to rule. So he has his own gear and different tactics when fighting, which makes the fight quicker and more strategic for the player mainly because they would almost be fighting themselves.
And since there is a strong similarity between the challenge of fighting this new main baddie and that of Dark Link, I decided to play with the corruption of the Prince's soul even more to actually give origin to Dark Link. Of course, this becomes a less original take, but nonetheless, it provides a new challenge up until the final point of the game (where he transforms or not).
Anyway, that's just a side example. I constructed an entire game with new enemies, mainly because Hyrule Kingdom is one of 20 or so other kingdoms. I've since tried to pair back slightly, using other kingdoms in sequels (which drives me nuts), but it's for the sake of scale in regards to game size and content. Anyway, there's just way to much to not explore when you have an entire world to work with...so if anyone wants to inquire about the specifics, feel free. If not, stay tuned for anything labeled under The Cardinal Kingdom, as that's my project title.
But here are a few new villains:
Gaburen, a mysterious man hailing from the
Kingdom of Darkness within the Twilight Realm, who serves as the vessel for the first act's villainy
Morphos, pale, fanged, clawed, active zombies (as opposed to slow, dark, Redeads) who disguise themselves as normal citizens and attack by clawing and biting you all over, quickly, having the ability to also run after you (predominant in the
Land of Fiends)
Sarpins, essentially Morphos with wings, but they are more intelligent and are capable of wielding weapons if the opportunity arises (predominant in the Land of Fiends)
Troyles, a large, stone, troll guardian with two horns on its head, moving around on all fours with the ability to create shockwaves by stomping, and charge into you after building up momentum (predominant in the Land of Fiends)
And Wolfos variations-
Omega Wolfos and
Alpha Wolfos, part of the Wolfos Prime pack that stalks and antagonizes Link and Zelda while they journey the Land of Fiends, the
Forest Kingdom, and
Leo Kingdom.
Then there's also Hadians, but they are just another race like Hylians or Ordonians, who are a little slimmer in comparison to their counterparts, with an almost blue/gray tint to their pigmentation. There aren't necessarily villains, but being in the Hadian Village, you are more susceptible to these impoverished citizens attacking you, which makes them possible threats, whereas in Hyrule, no one engages in such extreme measures and fighting or killing someone could warrant you trouble. In the Land of Fiends it's a possible blood bath.