TCD

TCDs (TEE-see-dee, or sometimes said "tea kid"), short for Trans-Dimensional Communications Device, are sadly an increasingly common possessive machine that is used for controlling people of lower tiers.

Description
How these machines work is still shrouded in doubt. They are sent to a specified time period, in which they disguise themselves as a common household item according to when they were sent to, or sometimes a child's toy. They always start out with removable tags and hold a psychic link with the sender that will automatically form a psychic connection between whoever touches it and the sender of the TCD.

This psychic connection works much like telepathy, but in a much more possessive manner. The reason why TCDs are so dangerous is because the 'toucher' will not immediately notice that the psychic connection has been formed. The TCD itself also "links" itself with its toucher and will emit a series of telepathic, subconscious waves whenever the toucher is at a distance that influence various strange behaviors, including a sudden desire to "go get something they forgot".

The victims of TCDs usually don't notice at all any change in them, since the TCD's emitted telepathic waves are aimed at their subconscious and they believe that it is just them getting attatched to the TCD. At a certain time, however, the TCD will influence behaviors of cutting off its tag. Once this happens, the original sender of the TCD has near-full control over the person who has the TCD - so long as that victim is either holding/touching or at a certain close range to the TCD. The victims become zombielike and will develop horrible short-term memory as well as arrogantness.

Downsides
TCDs are somewhat unreliable. They work on any tier, but an individual victim could easily snap out of the trance sent by the owner of the TCD if they were strong enough, or ignore the subconscious waves emitted by the TCD that influence the strange behavior. Even a mortal could do this if they really tried. This is why TCDs are targeted at people who have less self-esteem, are disabled, or have little willpower to resist. Also, if the TCD gets damaged by fire, water, overload of electricity, etc., the psychic connection is severed immediately and cannot be fixed unless another TCD is sent. TCDs are nasty devices but don't always work the way they are expected to work. The easiest way to snap out of a connection is to reset the TCD's hardware, which will also sever psychic connections but will make it still able to snag a victim away.

Also, once a TCD assumes a specific form, they can never switch out of it. There are currently 19 TCDs scattered around the Earth, and many people have learned to recognize them by their iconic appearances. 5 of the patterns are known worldwide, but the other 14 remain a mystery. The most famous one assumes the form of a small, stuffed giraffe, but which has been reported to have been burned by an unknown being for unknown purposes. The owner of this item has never been found.