The 25th Aethyr, VTI, is the region where you first become aware of the beast. The beast is a developing theme in the Aethyrs. The beast will next show itself in the 16th Aethyr, LEA, and then later on in some others in various more rarefied forms. The atmosphere in this Aethyr is the things that lie beyond logic and reason: the psychic forces that connect the super conscious with normal human consciousness. As such, in this Aethyr you are in between a conscious and unconscious state as far as your divine personality is concerned. Hence the reference to the beast.
The beast in VTI is your newly raised up ego from its previous state in DES. At the novice stage in VTI, your consciousness will seem wild and untamed. You will be susceptible to the spiritual pride that permeates this Aethyr. You see! Even though you have successfully raised your consciousness to a more rarefied form, it is still joined to the lower personality. This union distorts your spiritual vision for as long as it takes for you to purify the lower components of your personality. For most students this work can take many years. It is alchemy in its most true sense; the alchemy of the human soul into its divine nature. That divine state is an ever progressing upward motion that gets completed in LIL, the first Aethyr, where your beast matures into a young child of divinity.
The name of the guide in this Aethyr is TAOTZEM, which breaks down to mean "He who has your own likeness." This angel is actually none other than your own self above your ego. He is a reflection of your Holy Guardian Angel who awaits in the 8th Aethyr, ZID. The guide's job here is to show you those psychic forces that lie above logic and reason -- forces which are pale in comparison to the psychic forces that manifest on the physical plane, and are miles away from mere logic and reason. He demonstrates to you the correct use of these skills and tries to subdue spiritual pride within you. Because of the powerful psychic skills and forces in this level, spiritual pride can make you think that you are better than others who have not reached this level -- a danger and the first challenge to remove from your beast.
* additional source material: "Enochian Magick" by Gerald J. Schueler, "The Golden Dawn" by Israel Regardie