The range of noncorporeal manifestations in SSSS does not stop at souls detaching from a living creature and spirits that have an active life of their own, but also includes ghosts, usually rather passive remnants of beings (humans?) that have died that nonetheless stay behind in the real world.
Characteristics
While the Nordics may not fully agree on the details, they all pronounce it standard procedure that the spiritual parts of deceased humans leave the world of the living to continue their existence in a netherworld, with only a select few ever being able to return from Valhalla, Fólkvangr, Hel, Tuonela, or other places of afterlife. Hence, the case of a ghost staying in the world of the living instead is an extraordinary one.
It is currently unclear whether "A", the dead Danish priest who has so far only manifested in the dreamscape, should be considered a "soul", "spirit", or a (rather atypical) ghost.
"Default" ghosts
Judging from the appearances seen in the comic so far, SSSS ghosts share a couple of traits with the pre-Rash concept of ghosts; namely, they seem to be the direct product of a dying human, and bound to stay at the whereabouts of his death. On the other hand, they rather have the opposite color of the prototypical "bedsheet white/grey" ghosts of pre-Rash times. The ghosts could be a possible product of unnatural death as they first appeared in the hospital where the vaccine was being tested, they could have been tested on for a cure as they all had the rash illness but died before it killed them.
The jury is still out on how much of a danger such ghosts are to humans. Those in Amalienborg started out way more passive than the horror movies of old would ever have allowed them to be; as Reynir puts it, "they just kinda sit there and flicker a little." Nonetheless, they later killed a troll and appeared in a very vivid dream of Reynir, though Reynirs fylgja seemed not to consider the situation outright dangerous.
The ghosts that three of the protagonists met at Kastellet, however, appeared more threatening right from the moment we were first shown them - at which point Mikkel had already disturbed their site of death, though. Many readers assume that the ghost brigade later attacking the crew at Amalienborg consisted exclusively of ghosts that had come from Kastellet, rather than taking their Amalienborg kin along.
"Murderghosts"
It is shown that ghosts, even the passive ones at Amalienborg, possess the ability to absorb the lifeforce of humans, trolls, beasts, and very likely also animals that they can touch. The victim's body stays behind, and simultaneously the ghost's appearance changes to include features of the victim. Also, "experienced" murderghosts do not appear dark anymore, but show a translucent white shape.
The most prominent murderghost - currently nicknamed "Sleipnope" because of its eight-legged equine appearance, mainly due to absorbing first a multi-limbed sjødraug
and then a beastified horse - exhibits notable intelligence in that it leads a couple fellow murderghosts into herding trolls, presumably to send them stampeding at the expedition. It is theorized that the Great Defeat of Kastrup, which still leaves the Danes puzzled for what exactly happened, was similarly masterminded by murderghosts.
Known Occurences
- Upon entering Amalienborg
, Reynir notices movement in one of the palaces, which turns out to be ghosts hovering around the beds containing skeletonized bodies. Apart from an absent Lalli, the other team members, in particular Sigrun and Mikkel, seem unable to see them. - Later on, a similar room of bodies at Kastellet seems perfectly normal to Mikkel and Tuuri, but looks outright teeming with vengeful ghosts to Reynir.