Five Minecraft Mods That Improve the Nether
When players first step through a portal into Minecraft's Nether they are often impressed by the area's truly intimidating atmosphere, but before long the dimension's severe lack of content pushes them away. While there are a handful of useful items to be collected and a few new monsters to slay, there is only a single biome type covering the entire area, only one new plant, and there is almost no reason to continue exploring after finding a single Nether Fortress. The dimension also suffers from a high reliance on grinding to collect desired items, often forcing players to stand next to Blaze-spawners slaying the infinity-respawning fire elementals, or to wander through already cleared fortresses hoping to encounter fresh Wither Skeletons so they can attempt to collect their skulls. Unfortunately, there are very few mods that are actually focused on the Nether, and most that do improve upon this underdeveloped dimension do so as part of much more sweeping changes to the game, and may barely mention in their descriptions that that they add anything to the Nether at all. So I have decided to list in one place the five mods that I feel enhance the Nether the most in looks, variety, and gameplay. Each of these were chosen for their compatibility, configurability, and relevance; all of these are able to function in Minecraft version 1.7.10 at least, and all of these can be heavily adjusted and will work with nearly all other mods.
Biomes O' Plenty
While Biomes O' Plenty is a mod that focuses primarily on the Overworld, its also includes several important changes to the Nether. The first of these that a player will notice after crossing into this world is one of the six new biomes: the Boneyard, Corrupted Sands, Phantasmagorical Inferno, Polar Chasm, Undergarden, and Visceral Heap zones. These manage to work well with the Nether's original feel, and while they are all intended to look like rather unpleasant places to live, they are varied enough that you can instantly recognize each zone. There are forests of stunted trees and deadly plants, an area full of massive pillars of bone, and even an extremely rare place where the Nether has frozen over. Despite their diversity, all of these zones fit perfectly together and with the original Nether biome, and there are none of the sometimes jarring lines between areas like those that sometimes happen around the edges of Overworld biomes.
But there are more than just visual changes added to the Nether, several of Biomes O' Plenty's Nether changes effect gameplay as well. The most important of these are the rare blood pools that act like water from the Overworld, but unlike water, blood does not evaporate if used in the Nether, meaning it can still be used to irrigate crops or put out fires. There are also new phantom enemies that will send you flying if it can get close to you, and massive wasp hives dot the roof of the dimension, each of which is guarded by deadly wasps that will attack anyone who gets close to the honey within. And many of the biomes have something extremely valuable within them, such as the massive bones sticking up in the Boneyard that can be ground into fertilizer, the trees in the Undergarden which might be your only source of wood in this dimension, or the ash generated in the Phantasmagoric Inferno which can be mixed up and turned into coal, all of which gives you plenty of reasons to explore and possibly even settle in the Nether.
Natura is another general-upgrade type of mod that adds a lot to this fiery dimension, but unlike Biomes O' Plenty it doesn't touch the biomes themselves. Instead it creates several new types of flora, fauna, and useful items for the Nether. There are several new types of interesting trees, such as Ghostwood: which has transparent doors and planks, Bloodwood: which grows upside-down from the Nether's ceiling, and Fusewood: which explodes when you attempt to cut it down. Natura also adds four types of berry bushes to the Nether, each one of which will produce magical berries that give some very useful effects, such as short-duration night vision or healing, and will sate your hunger, but also give a small status ailment such as poison or slowness. There is also a somewhat rare new glowing vine called a Thornvine that damages any entity that touches it, providing another interesting way to defend parts of your base. But probably the coolest-looking bit of new flora added are the glowshrooms, slightly transparent glowing mushrooms that can come in either small or large forms and in three different colors, and if you can collect mushrooms of all three varieties they can be combined into a stew that gives you a long-duration night vision effect.
There are also three new creatures added by Natura: the Imp, the Nitro Creeper, and the Heatscar Spider. Imps are short, tough, breed-able creatures with poisonous meat that will light you on fire you if you eat it, but whose leather can be turned into useful heat-resistant armor. Meanwhile the Nitro Creeper is a new variation of vanilla Minecraft's iconic Creeper, one who does less damage, but explodes almost instantly upon coming within range. Finally there is the most dangerous of the new creatures, the Heatscar Spider: a huge and deadly spider that when slain will burst into a pack of two to four "baby" spiders, each just as large as the giant spiders of the Overworld.
And there are a few other interesting items and bits of world generation added by Natura. There are several clouds of sulfur and ash floating about the Nether that can be collected and turned into gunpowder or charcoal, or moved to the bottom of a drop to prevent fall-damage. There are also special-colored weapons and tools for all of the Nether trees as well as new quartz tools, and some of these are actually nearly as powerful as diamond weaponry. The developer also implemented a new netherrack furnace that can be made quite easily, meaning that players won't have to go back to the overworld or haul a stone furnace to the Nether to cook their food and materials. But by far the most important item added by Natura is the Obelisk, a machine that can be activated to set the player's spawn to a point in the Nether, meaning that if one wishes they can live, die, and be reborn without ever leaving the underworld.
While the previous two mods add more life to the underworld, Gany's Nether focuses more on implementing new ways to gather the dimension's various resources, and adding in new machines and items using the materials gathered there. There is a good variety to the types and prices of the new items, with some cheap and useful items such as the Soul Chest, a chest that sucks in nearby items and only requires soul sand and a piece of quartz to build, going alongside more expensive tools like the Volcanic Furnace, which allows you to turn anything into lava, but costs several diamonds and obsidian blocks to create. That lava can then be used to fuel Thermal Smelters, a type of furnace that can use some of the heat from adjacent lava sources to fuel itself and never burns through its fuel, however unless there is a lot of lava around the smelter it won't even come close to the speed of a normal coal furnace. You might also build a Magmatic Centrifuge and use all of that lava to mutate items into related objects, such turning rotten flesh into leather, or magma cream into slimeballs and blaze powder. But arguably the most powerful set of items added by Gany's Nether are the Sceptre of Concealment, the Reproducer, and the various upgradable mob-spawners, all of which are built around the idea of capturing creatures, turning them into any type of beast you need, and then spawning in an infinite number of them.
But machines aren't the only new things you can build, there are several other useful items added by Gany's Nether. Some of these are new weapons, like the magical scepters which can shoot lightning, throw fireballs, or trap your enemies inside of chicken eggs. There is also a tough new armor made out of Blaze Rods, but make sure not to fall in water while wearing it as it will dissolve quite quickly. New forms of lighting have been added thanks to glow boxes, small rectangular blocks made of glowstone and glass that can be dyed and give out the same amount of light as normal glowstone. And Nether quartz has received a similar treatment, with new normal and chiseled blocks, stairs, and pillars, all of which can be dyed in one of sixteen colors, allowing you to paint your base any way that you might wish.
However, arguably the most useful new addition, and in my opinion the most welcome one, are the new resource-generating crops. There are now seven new types of plants spread throughout the Nether, such as flaming cacti and transparent wheat, and these can be collected and replanted allowing for a very unusual form of farming. Most of these plants require nearby lava to grow, as well as netherrack tilled by a golden hoe, but others might just require netherrack, and one can only be planted on the side of a block of obsidian. Once grown, these plants can generate nearly all of the normal set of Nether resources such as blaze rods, lava, quartz, soul sand, and there is even one incredibly rare plant that lets the player grow wither-skulls, letting someone lucky enough to find it completely skip the most tedious item hunt in the game if they manage to run across such a plant.
But as great as the new plants, machines, and items added by the aforementioned mods are, you really cannot have "hell" without the demons. Lycanite's Mobs was originally a mod designed to add the various monsters from the Doom games to Minecraft, and while it has since evolved into something so much larger, it's original creatures are still the best looking, most useful, and horrifyingly dangerous monsters added to the Nether by any mod. They all start out as aggressive, and are often just as dangerous as the worst of the Nether's original monsters, but with a little love many of them can become valuable allies. For instance, the Pinky, a large-jawed bipedal beast, can be bred by feeding it live cows, sheep, or pigs, and then the babies can be given treats and tamed. One they grow up they can then be used as powerful mounts that prevent the player from being affected by the wither ailment, will attack their rider's enemies, and can use a powerful roar ability on command, inflicting all nearby enemies with wither. Cacodemons can also be tamed and equipped with armor or chests, allowing you to make powerful guards or pack mules who can be set to follow you or to guard your base. There are also two beasts that can be summoned with a special summoning staff if you can manage to look at one through an item called a Soul Gazer, giving you some rather powerful allies when you need them. And while the other three monsters cannot be tamed in any way, they do drop useful items that cannot otherwise be found in the Nether, so hunting them can be well worth it for one who wishes to remain in the underworld.
And demons are not all that lives within the Nether, all of the lava and fire makes it a great home for Lycanite's inferno creatures. All kinds of fiery beasts appear when near heat sources, and while most are aggressive at first, all but one can be tamed, summoned, or bred. Unlike the Doom-monsters, the inferno creatures come mostly from more general fantasy as well as the developer's own creativity, and they can have some interesting effects. Some might burst into lava when slain, others might throw balls of magma, and there is even one completely peaceful fish-like creature who can be bred for food. They all fit in perfectly with the demons, and together raise the total number of creatures you can encounter in the Nether by eleven, all of which can be useful to some degree.
And as odd as this is, my final choice of mods that enhance the Nether is Better Foliage, a mod that improves upon the appearance of plant-life in Minecraft. This is a bit of a strange choice, considering that without additional mods Better Foliage only changes the Nether in two ways. And while those two changes are indeed great, with the rising souls especially helping give areas with soul sand a lot of extra appeal, alone the mod is just a nice little tweak. But when you include the likes of Natura and Biomes O' Plenty, the Nether becomes the one place in all of Minecraft where you can enjoy all of Better Foliage's capabilities at the same time. With Natura, you might see souls float up and get caught in the leaves of a Ghostwood tree, or first realize that one of the hanging Bloodwoods is growing above you when its leaves drift down to the cavern floor. Biomes O' Plenty also benefits quite well, with its Undergardens gaining almost every upgrade Better Foliage can apply, and the souls drifting up from the Corrupted Sands biomes completely changing the feel of the zone. Better Foliage might not seem like the first mod you would want while exploring the underworld, but when combined with other mods its improvements will follow you throughout all of your adventures in the Nether.
One Final Honorable Mention: Matmos
There is one other strong Nether-enhancing mod that I can not really recommend for everyone, but is certainly worth considering: Matmos. Matmos is an ambient sound generator that enhances all of Minecraft, and it can improve on the Nether's feeling of creepiness more than any other mod. The exact sounds are dependent on the resource pack used, but you can expect the Nether to be noisier and much more menacing than the original game, where the ghasts, pigmen, and lava were almost the only sources of sound in the entire dimension. However, while the developer has upgraded it so that it works with 1.7.10, he has not produced a resource pack, and searching up and installing a user-developed one can be a bit of a pain. More problematic is that the mod is not particularly stable, and you can expect the occasional crash when running it. But those two problems are the only reasons that it is not on this list, so if you are willing to tolerate them I highly suggest it.
Whatever your reason for wanting to enter the Nether, you should be able to enjoy it much more with these mods installed. They are those I consider the greatest currently updated Nether-enhancing mods out there, and they are compatible with nearly all other mods you might use, whether in or out of the underworld. Their configuration options allow them to be tweaked in any way you need, and nearly any part of all five mods can be disabled or enabled at will. And while there are indeed others options available for versions prior to 1.7 that can upgrade the Nether just as much, those have not been updated in nearly a year and seem to have been completely abandoned. So if you intend to play Minecraft version 1.7, all of these mods are great options for spicing up the underworld. As for 1.8 players, they can already enjoy both Biomes O' Plenty and Better Foliage, and there is a good chance that the other mods will be updated before long.