Zalgo was sealed away by Sadiya hundreds of years ago, starving away and slowly being drained away of its powers to prevent more Demi zalgoids and a catastrophic world collapse.
It was one of the candidates during birth that could become ruler, and thought for its place.
It became the strongest zalgoid by slowly devouring those weaker than it, becoming more and more powerful.
After it was sealed off it was instantly dethroned and out powered by some other candidate.
Zalgo is immortal and absorbs lives from those he eats to continue living, during captivity it was starved of souls by Sadiya, Kaidy, Stripes and Pandora, but kept alive by essentially being on constant life support so those ghosts don't get absorbed into him.
Once someone dies they become immortal by borrowing from the souls in Zalgo, if they were to die again their souls are kept "alive" inside Zalgo, taking back what was borrowed.
Now Zalgo is in a weakened, melting state waiting for another chance to escape.
It escaped the seal because of Stripes and was partially eaten and put back by Lazari.
It was the only one able to fertilise eggs and has so many kids to ensure some will make it to adulthood and eats the defective ones as they wouldn't survive the environment.
Zalgo has a lot of kids, thousands even and very rarely will the kid turn out to be male.
It doesn't connect with any because it sees it as just progressing the species.
Zalgo started having kids with humans to try and make zalgoids survive longer.
Its many followers assumed it would have high standards and taught them with that in mind.
Zalmans are frequently born, or develop later on, health issues, more likely to suffer from injuries, sterile and neurological disorders.
Zalgo has many folklore and cults surrounding it, many believe it is a devine being that will rid the world of its sins.
Zalgo can shapeshift, it rarely ever shapes into a human form and only if it absolutely has too, usually when it's breeding with humans. Its human form isn't consistent, its appearance changes depending on the person it was pursuing.
Its powers include resurrecting the dead, shapeshifting, teleportation, possession and reality warping.
It brought Scarecrow alive because it wanted to know how he would react when his friend became alive and want the scarecrow would do.
Zalgo is very curious about human nature even if it doesn't necessarily care about them.
It can speak every languages because of how old it is, but its speech is glitched and scrambled, making it difficult to understand to humans and zalmans.
Zalgo has a lot of kids, thousands even and very rarely will the kid turn out to be male.
It doesn't connect with any because it sees it as just progressing the species.
It doesn't have a known, consistent look, a lot of people have different interpretations on its appearance and behaviour.
Slenderman
It's a pathogen that causes severe audio and visual hallucinations that specifically targets traumatised and other vulnerable individuals as they're the most susceptible in order to spread itself through contact and make the host lose their mind.
Most Proxies believe it is their saviour and dedicate their life to it and kill because they believe it is what they want from them while it slowly drives them mad and taking over their motor neurons eventually killing them.
It also surrounds the brain and releases chemicals to influence behaviour when not in control.
Its Proxies are Kate the chaser, Charlie jr, Rouge, Wilson the Basher, Labrador, Aleida, Rosie, Hunter, Hannya and Ellie.
Slenderman Proxies have self proclaimed ranks, these being:
The Hallowed - Those who have been totally dominated by it and act only upon its will. Brainless, emotionless drones essentially. Useful for attacking and spreading but otherwise useless. From many limited interactions, they just sit around in a catatonic state when it's not leading them like puppets.
The Berserkers - Those who are under its control but can act on their own when it isn't commanding them. These are far more dangerous than the Hallowed, because they can work their way into positions of trust to further its agenda. They often think that they are Agents, but they are not.
The Sleepers - Those who are under Slender Man's control, but are unaware. They come under its control when their mind is at its weakest, during blackouts or when asleep.
The Agents - Those who act for it, despite not usually being under its control. Whatever their motivations, if they act on its behalf, then they are Agents. One of their biggest assets is that they're (if they are not proxified) totally sane and retain all of their mental faculties, which means they can target people in ways far more creative than anything that the Tall One itself can think of. They are the equivalent to cultists.
It has a one track mind of infecting, that is all it knows and cares about, slowly infecting people with the Slender Sickness.
It sticks with its victims for years or even decades if necessary until it's decided they have no use.
When it encountered Lazari, it stalked and mentally tormented her for 1 week, but got confused and didn't affect her, not knowing what they really are, looking vaguely like a human but feeling different.
She got frightened and transformed into their Zalgoid form, making it not interested.
It thrives in warm, humid environments which is ideal for its growth and feasts on dead bodies and technology, which is how it ruins electronics.
There is a group working trying prevent and kill any infected called the anti body.
