Due to referring themselves as "We" instead "I", and multiple victims are shown possessed at the same time, they are rather in large number and often controlled by the power of the Necronomicon.
The person possessed by the Deadite is totally overwhelmed by the Kandarian Demon's main consciousness, with the resulting Deadite having access to all the hosts memories and behaviour. By all means, Deadites are the Kandarian Demons, and the Kandarian Demons are them. Deadites are demons from "Hell", though it is unknown whether this is the Hell of scripture, or merely the Deadites referring to a similar place of torture. Deadites are like an efficient network, all connected to each other (see Cheryl and Linda; Ed and Henrietta), suggested that both The Force and Deadite are connected via hive-mind and support the fact that they are multiple in large but unknown numbers.
The Human Deadites in their first and default stadium display white eyes with no pupil, reverbered voice, abnormal facial features, sharpened teeth, altered hands, skin tone change (grey, yellow, rosey or white) and differently-colored blood and fluids (white, dark or light red, black or green). The main abilities of a Deadite include superhuman strength and stamina, levitation, invulnerability to knife cuts and minor gun shots that are not involved with the brain. Over time, they can morph their overall body structure, or even grow extra limbs from the inside of their bodies. The most dramatic change they can substain is the conversion into a bat-winged brownish creature which no longer resembling former human form anymore. Deadites can also create hallucinations that change their aspect in order to deceive people, but the effect lasts just a few minutes. Deadites can survive extensive damage to their bodies (see Henrietta, ED2 Linda). If trapped or blocked, they can immerse themselves into an apparent sleep condition and awake in convenient times (see Henrietta). The hosts body deteriorates alarmingly fast, sometimes as little as a few hours resulting in visible bone and flesh.
Possession is vastly achieved with a direct interface and "fusion" with the incorporeal essence of the Force(The Force start off possess someonse before summon it's minion to possessed other), a drastic mean to speed up the production (or summon more disembodied Deadite spirits to possess other potential victims) of Human Deadites (see Shelly, Ash). Another instance of possession is through being hit or violently touched by the possessed. The possessed would create a link between other Deadites and the touched host causing possession. In a slow process similar to a biological viral infection, the essence gradually increases within the organism, until the point the new Deadite release himself (the "Rotting": black ramifications can be seen on the skin a few seconds before the definitive conversion). Severed limbs or heads of Deadites can only transmit a limited amount of The Force's essence, but not enough to enable possession of an entire organism but at least part of it (see Ash's hand). Ash is one of the few to be resilient to the latter possession mode, though in Ash's case, The Force managed to took Ash's darker traits, enable it to physically manifests once more as Evil Ash.
The human soul inside the Deadite, while being painfully consumed and dissipated over time, can sometimes emerge and try to stop the Deadite, but only people of great will and perserverence can accomplish this.
Killing a Deadite is a difficult task. The rules are identical for each manifestation of both the Force and Deadite spirits coming from the Book of the Dead. The Deadite must be dismembered in a total way, decapitation is not sufficient, as limbs can continue to be animated. Multiple and high caliber gun shots can stop the Deadite for a limited amount of time, or kill if completely destroying the head, but dismemberment is necessary to finish off the Deadite so that the limbs have no host. The vulnerability of the head suggests that the Deadite relies on a few neural functions, though they can still survive with hardly any brain at all. It is unknown whether killing a Deadite in a host permanently kills the actual demon.
BackgroundEditHuman beings that have been possessed by a Deadite will exhibit white, pupil-less eyes, dark grey skin, and will also appear to decay rapidly. In The Evil Dead & The Evil Dead 2: Dead By Dawn, when people became possessed, they continued to decay indefinitely. It can be assumed that eventually the host body will decay completely from the demon's corruption. In The Evil Dead, Professor Knowby warned via his tape recordings that he feared the only way to stop those possessed by the demons (Deadites) was through the act of bodily dismemberment. Also in the same film, he warned that the book said that these enduring creatures may lie dormant but may never be truly dead.
When a human becomes a Deadite they that they have no control over their physical body. Their souls are allegedly taken to "Hell" and tortured, although this might just be the demons' threat to scare those not possessed. In the films, only two people that become a deadite was ever released or returned to normal, the most notable being Ash or Mia from the remake.
The Deadites also have complete recall of the lives of their hosts, their memories, their emotions, and their relationships, and are able to temporarily appear as fully human again to communicate with those not possessed. This has only been used to escape from certain death or indefinite confinement. Through this trickery, the Deadites provoke an irrational and emotional response in their captors or would-be killers to allow them an opportunity either for escape or to catch them off-guard.
The Deadites as creatures appear as beings of pure debauchery, lust, and insanity. They enjoy self-mutilation, swearing, and relishing the fear of their prey. Even in Evil Dead (2013), the Deadite, which in the movie also called Taker of Souls aka Shaitan, even display abnormal behavior by inflict terrible bodily damage to itself before even begin attacking others. It is unknown if it do this as a scare tactic or simply because they enjoy the pain. Oddly enough, after being a Deadite for several hours, suffering various injuries (mostly self-inflicted) including forking her tongue with a box-cutter, and being buried alive, Mia was completely unharmed after release from her possesion. This may imply that while possesing a human any harm on the body is inflicted on the demon rather than the possesed.
Cheryl Williams - most dangerous deadite in the first film.
Scotty - second most dangerous deadite in the first film.
Linda - less dangerous deadite in the first film / most dangerous deadite in the second film.
Henrietta Knowby - second most dangerous deadite in the second film.
Ed Getley - less dangerous deadite in the second film.
Evil Ash - most dangerous deadite in the third film.
Abomination - most dangerous deadite in the remake.
Eric - second most dangerous deadite in the remake.