The Aspect Theory

The Aspect Theory is the current theory held by this reality regarding the Slender Man, and was suggested by Corrupt Secrets, and confirmed by Choices.

Description
The Aspect Theory explains that the Slender Man, the Guardian, and every other related being is merely an aspect of a more powerful entity referred to as the Tall One.

Every seperate aspect of the Tall One exists in a seperate reality, and also seperates the people involved with it from other realities. Each reality and aspect exists independently of each other, although if the realities meet then sometimes the aspect of the Tall One combines along with the reality.