Multi-headed Each time the bearer rolls a 6 To Hit, they can immediately make another Attack. Any additional Attacks also benefit from this rule, so further To Hit rolls of 6 also grant additional Attacks.
Daemon Weapon At the start of the assault phase, roll a D6. On a 1, the bearer suffers 1 wound with no armour saves allowed, and is reduced to WS1 for that phase.
On a roll of a 2+, the bearer gains that many additional attacks.
Rending If a model has the Rending special rule, or is attacking with a Melee weapon that has the Rending special rule, there is a chance that his close combat attacks will strike a critical blow. For each To Wound roll of a 6, the target automatically suffers a Wound, regardless of its Toughness. These Wounds are resolved at AP2.
Similarly, if a model makes a shooting attack with a weapon that has the Rending special rule, a To Wound roll of 6 Wounds automatically, regardless of Toughness, and is resolved at AP2.
In either case, against vehicles, each armour penetration roll of 6 allows a further D3 to be rolled, with the result added to the total. These hits are not resolved at AP2, but are instead resolved using the model/weapon's AP value.