Do the Undead Exist as powerful Spirits or Ghosts ? (Personal Theory)

Theory based on Direct Observation in the Field Evidence based on (Russian Ghost Encounter)(Personal Theories)
Wraiths are very powerful Spirits which probably are elemental of water, forest, soil, and earth, and non Human based. They are a powerful form of the undead, and are intelligent, and clever, either that or a form of a very powerful entity. The location was an ordinary Graveyard that was well looked after, and tended, and in that respect was an ordinary Russian cemetery that the villagers were all buried in, including powerful families.
There was part of a Graveyard that contained rows and rows, of unmarked Graves, that were very small, which was near the front of the Graveyard towards the wall. That part was not so well kept, and had very long Grass, obscuring the Graves. It might be that such undead Spirits reside in areas where the Graves and fallen into disrepair, or are not so well looked after. The Wraith itself was I believe a Guardian or protector of the Dead. It was a powerful entity like creature, which did not fear daylight or human activity. It was moving around in broad daylight, so I am not sure how that can occur.
It was when I first encountered not in that part but towards the middle centre on a higher area, surrounded by Cherry Trees in Blossom. It was bending down to read the names and details on the Grave, and next to it were fresh Red roses. It was in the form of what I mistakenly I believe to be a grieving widow, as it was dressed all in Black. The reasons why it should not be approached, and was powerful, remain the fact that it could move very fast. It was only a few seconds from being towards the middle and back to appearing towards the front of the graveyard and when it was looking up at me and the people on the Coach. It has the power to shift form and is a shape shifter. It carried out a trick to frighten me which succeeded, of growing rapidly in size, to Seven Feet, and the area behind it and around it grew dark and Black. It was a trick to warn me off, and succeeded as I had no intention of entering the Graveyard.
I got the impression that it hated intruders and that it regarded the Graveyard or cemetery as its personal territory. It did not like the fact that I could see it, and I was fully aware of it. It was also fully aware that I could see it, and was puzzled by the fact, which was why it was drawn to me. The reason why it was undead was that its hands remained skeletal, but unlike a normal human, they were very long bony fingers, much more than normal.
There was nothing in the dark Cowl or hood, except a Human skull. The reason why the entity or spirit is evil is that I had the impression, that the force is a form of energy as the Skull was animated, by a dull Orange to red Light, which lit up the Sockets. The skull then was alive, and it grinned at me, and laughed before I looked away. It was a powerful trick again used to scare me and it succeeded. It was away for the Creature to challenge me, and tell me that the Graveyard and its contents belonged to it, and were its territory and to keep out and stay away.
I believe that entity’s or powerful undead, can manipulate there environments and space and time. When I got to the Hotel, there was a wood carving in the restaurant which was almost identical, to what I had seen, except it was more human. So I would say that such as entity is localised to that part or region of Russia, as it is present in the Folklores and tales. It was the inspiration for local Russian artists to carve it from there Folklore and tales. The strange fact remains that no one on the Coach and Tour saw the entity and spirit in though it was a few feet away, next to the Graveyard wall. Everyone else continued with there business while the spirit was looking up me and the Coach. So I do not really have answers as to why some people can see it and others cannot.