Warhammer 40k - Thousand Sons

Thousand Sons are a sub-faction inside the Warhammer 40k Heretic Astartes / Chaos Space Marines faction, and distinguish themselves with weapons and rules unique to them.

Originally hailing from a planet known for its high number of psychic humans, events during the Horus Heresy rebellion 10,000 years ago, saw them turn traitor and every last non-psyker Thousand Son marine trapped in their armour as disembodied spirits. Guided into battle by living sorcerers devoted to the Chaos God Tzeentch, the Thousand Sons pursue seemingly random, sinister plans and conspiracies across the galaxy in order to expand their own influence and that of Chaos.

Psychic powers feature heavily in a Thousand Sons army; if the opponent does not have a way to nullify this, the Thousand Sons dominate with psychic might bolstered with their patron gods immense power, they fling flame and force with the same expertise as their bolters and swords. 

The Thousand Sons are a very unique army to play, an elite force that are deceptively durable, wield incredible firepower as well as dominating the psychic phase of the game. 

They are lead by Magnus the red, the Daemon Primarch. Once the strongest psyker of all the primarchs, he was betrayed in many ways which lead him on a path of treachery eventually leading him to become an Avatar of Tzeentch, the God of fate and change.