Xhinn

The Xhinn are a race of conquerers who travel from planet to planet stripping it of resources in order to conquer more worlds.

Physiology
Xhinn are roughly humanoid, though they are described as being made of darkness and light. They have tentacles instead of hair and have hundreds of eyes on their face. They don't have any mouths and communicate telepathically. Though Xhinn naturally have extremely long lives, they can increase them by absorbing energy from other Xhinn. Xhinn are also highly flammable.

Xhinn have a variety of advanced powers. They can shoot blue beams of energy out of their hands and can teleport anyone who is hit by this energy. They can regrow limbs after losing them and can control these lost limbs from a distance. They can also levitate and prefer it to walking. They can also become exact copies of Humans, including their appearance and memories.

Technology
The Xhinn travel in shadowy spacecraft which are nearly impossible to track.

During their invasion of London, they added a special chemical to the fog to poison and kill the inhabitants. They also used a special drug which can control the minds of Humans. This drug is so effective that if they person is fatally wounded, the drug will keep them moving.

History
Legends state that 5 million years ago, the Xhinn were created out of fire in an alternate universe. They rebelled against this creator and were banished into the universe. They then started on a divine mission, led by the Triumvirate, trying to get the entire universe to worship them as gods. They were a highly methodical species, spending years studying species in order to find their weaknesses.

In 1900s, the Xhinn sent a scout to Earth in order to learn about the planet. They sent two Xhinn to join the Humans, trying to learn about them. One of these scouts went against the plans in 1952 and forced them to poison the fog of London to cover up their tracks. These attempts were stopped by the Doctor and Sarah Jane Smith, along with the help of the local gangsters. The Doctor was able to create a Time Bomb which aged the Triumvirate past their natural life-span and destroyed their spaceship.

The main Xhinn fleet was due to come to Earth in 2002. (PDA: Amorality Tale)