Possessed

At the beginning of each sub-fight phase, roll a single  D3 for the entire and consult the table on the Possessed Profile in Codex: Chaos Space Marines. This awarded mutation lasts until the end of turn.

Models with the Daemon special rule have a 5+ invulnerable save, and also have the Fear special rule.

Units containing one or more models with the Fearless special rule automatically pass Pinning, Fear, Regroup tests and Morale checks, but cannot Go to Ground and cannot choose to fail a Morale check due to the Our Weapons Are Useless rule. If a unit has Gone to Ground and then gains the Fearless special rule, all the effects of Go to Ground are immediately cancelled.

A unit composed entirely of models with this special rule can re-roll one or more of the dice when determining Run moves and charge ranges (such as a single D6 from a charge range roll, for example).