Negative Energy

Negative Energy is a phenomena that fueled the genesis of undead to naturally spawn in the New World.

Overview
Different types of undead monsters are often born from the negative energy that is contain in a surrounding area. The process of an undead to be birth differs for some but functions similarly by the necessity of having negative energy to encompass its creation. In this case, to successfully craft a Skeletal Dragon must required two months of elaborate rituals and an immense quantity of negative energy for it to be possibly achievable. With ample negative energy existing in several regions of the New World, there are always bound to be a spawning ground for where a frequent amount of low-ranking undead would roam about aimlessly. As many undead entities have negative energy, so are their feelings toward the living being negative with a few exceptions. Evil magic casters in that regard, who was once part of the living after dying will face an unnatural rebirth, becoming part of an undead race where its body is now made up of negative energy.

Mechanics
Among the undead, there are creatures like Elder Liches who possessed a skill that allows them to inflict negative energy damage on anything they touched. Particularly, those who are part of the living as it could prove to be detrimental to their health. Compared to the undead, negative energy flowing into a living creature’s body will only served to rob them of their vitality or positive life force. It was possible for this ability to be deactivate temporarily by the user. In order for the living to protect themselves from negative energy, one may need to consider casting the defensive spell, [Protection Energy - Negative] on themselves against it as resistance. Wearing a fully-equipped armor alone doesn't defend oneself from a negative energy touch. The ability-damaging negative energy touch can easily bypass through the living being's armor and harm them without problem.

The undead's body has a life force that is filled with negative energy. The corpses are commonly known to reanimate and move based on that energy given. As long as their negative life force continues to remain in the world, any undead would continue to linger on without disappearing. In the case of a Plague Bomber, it was willing to weaponize its own body's life force of negative energy to inflict damage to the living while healing nearby injured undead kins at the cost of its unholy life. Although undead couldn't feel pain, they can still feel their negative life force dissipating or being taken away from them. As an aside, moving Zombies would not rot or harbor maggots because they were animated by negative energy. Instead, the loss of negative energy once they were defeated meant that they would rot as normal, flies could lay eggs in them, and small animals would gnaw on them.

Spells like [Greater Lethal] and [Ray of Negative Energy] are made of negative energy served to help them survive despite taking damage by positive energy. For instance, wounded undead entities can received any types of healing from them as long as it connects to the negative energy provided. Using negative energy attack spells on undead-type foes won't deal any damage to them whatsoever as that will only served to heal their wounds off from it. This could even affect an undead's hair being restored back to its original length after cutting it with normal means like a scissor. Furthermore, non-living objects like doors would take less damage from negative energy bursts while the living sustain more than their counterpart.

However, negative energy and undead can go on existing spiritually without needing to have a physical form as Elder Liches. The only way to drive away the negative energy in areas that contained it is with using holy/divine power through a priest, cleric or magic item capable of doing so. Once the cleansing has been thoroughly done, the air in such an area that was initially filled with negative energy will now have its own fill of freshness as if a cool breeze had just passed by. Depending on the amount of negative energy surrounding an area, it will sometimes be proven possible or impossible for prayers to cleanse. For the latter case of E-Rantel's Cemetery, massive prayers will not be enough to completely purify it all away due to the many souls whose resentment lingered upon that graveyard, causing the negative life force or energy to converge together.

On the other hand, individuals like Evileye possessed a special ability that would cause the negative energy flowing through her body to overload. Through doing so, she can then infuse every attack spells she cast imbued with negative status effects. Spells like [Undying Flame] can do something similar like it, adding negative energy and elemental-type as fire damage together. In other words, this could suggest the notion that enhancing one's spells with negative energy can grant the user the power to inflict negative status affects. Particularly, such negative status effects ranged from poisoning, deafness, fatigue, blindness, and so on. They were all ineffective against an undead, but not with the living. Though the slime, Bukubukuchagama and Primal Elementals are resistant to the negative status effects which undead would normally inflict on others.

Additionally, there are items like Orb of Death that requires consuming a specific amount of negative energy to make use of its ability by the user. Summoning powerful undead creatures through an item like it as catalyst consumes a lot of negative energy. One of the ways to quickly recover all the depleted negative energy is to spread mass amounts of deaths throughout different areas such as a city. One could store all the negative energy comprising of undead, in order to create a birthing place for higher-tier undead to spawn among the lower-tier ones.

In the case of becoming a supposed high-tier undead creature as stated by Khajiit Dale Badantel, one got to gather a massive amount of negative energy by killing an entire city's worth of people. Afterwards, turning them into low-tier undead minions to harness the negative energy they would generate upon conversion. Hence, one can create the undead just from harnessing its negative energy. This has been the objective for conducting the Death Spiral ritual, gathering all the negative energy acquired from it in one place before then sealing it into oneself, successfully turning the caster into a powerful undead.

The emitted negative energy covering an Elder Lich's body like Iguva=41, and the ones from the Great Tomb of Nazarick appears like a thin fog around it. It was the same with the frequent sighting of fogs enshrouding throughout the undead region, Katze Plains. The most dangerous thing was the thin mist that wrapped around its undead monsters no matter the time of the day. This fog carried faint traces of the negative energies which caused undead reactions. By itself without undead around, the mist's negative energy did nothing to living creatures. It did not absorb life energy, nor was it a harmful thing. Unfortunately, because the mist registered as an undead creature to spells, it produced false positive reactions. This resulted in foiled attempts to detect other undead beings who were closing in on foes all this time, and as a result many adventurers had been ambushed by them while inside it..

Trivia

 * It's currently unclear whether Negative Energy have a direct connection with a person's Negative Karma Value.
 * There are also skills like [Negative Protection] or spells such as [Negative Burst] that may have some correlation to Negative Energy.
 * In YGGDRASIL, there were negative mind-affecting effects that can effect the living.
 * YGGDRASIL's undead players like Momonga possessed the ability to infuse negative energy by touch, yet it cannot heal the undead. Apparently it could have heal undead by touch during the first week of the game, but it was immediately patched out.
 * In other games, killing someone who had gained an incurable status affliction, beating them into a near-death state and then resurrected would eliminate the negative status effect. Compared to such games however, it could not be done that way in YGGDRASIL.