The Obsidian Knight

This rule is often presented as Preferred Enemy (X) where X
                        identifies a specific type of foe. If the special rule does not specify a
                        type of foe, then everyone is a Preferred Enemy of the unit. A unit that
                        contains at least one model with this special rule re-rolls failed To Hit
                        and To Wound rolls of 1 if attacking its Preferred Enemy. This applies both
                        to shooting and close combat attacks.

At the start of each Fight sub-phase, a unit in base contact with one or more enemy models that cause Fear must take a Leadership test (called a Fear test) before any blows are struck. If the test is passed, all is well and there is no effect. If the test is failed, the unit succumbs to fear - all models in the unit have their Weapon Skill reduced to 1 for the remainder of that Fight sub-phase. Note that a model that causes Fear is not itself immune to Fear, and will still need to take a Fear test if it is base contact with any enemy models that cause Fear.

If a model with this special rule ends its charge move in base or hull contact with an enemy model, it makes one additional Attack that hits automatically and is resolved at the model's unmodified Strength with AP-. This Attack does not benefit from any of the model's special rules (such as Furious Charge, Rending etc.). This Attack is resolved during the Fight sub-phase at the Initiative 10 step, but does not grant the model an additional Pile In move.

If a model with this special rule charges a building or vehicle, the hit is resolved against the Armour Value of the facing the charging model is touching. If a model with this special rule charges a building or vehicle that is a Transport or a Chariot, the hit is resolved against the building or vehicle, not the occupants or the rider.

Any non-vehicle model that suffers one or more unsaved Wounds or passes one or more saving throws against an attack with the Strikedown special rule moves as if it is in difficult terrain until the end of its next turn. It is a good idea to mark affected models with counters or coins so that you remember.

All of the close combat attacks, except Hammer of Wrath attacks, of a model with this special rule are resolved at AP2 (unless it's attacking with an AP1 weapon). Additionally, when it makes its close combat attacks, it can choose instead to make a single Smash Attack. If it does so, roll To Hit as normal, but resolve the Attack at double the model's Strength (to a maximum of 10). Furthermore, a model making a Smash Attack can re-roll its armour penetration rolls, but must abide by the second result.

Relentless models can shoot with Heavy, Salvo or Ordnance weapons, counting as stationary, even if they moved in the previous Movement phase. They are also allowed to charge in the same turn they fire Heavy, Ordnance, Rapid Fire or Salvo weapons.

A unit that contains at least one model with this special rule rolls an extra D6 when rolling to move through difficult terrain and is not slowed by charging through difficult terrain. In most circumstances, this will mean that, when moving, the unit rolls 3D6 and picks the highest roll. Furthermore, a model with the Move Through Cover special rule automatically passes Dangerous Terrain tests.

A Super-heavy vehicle is so large and strongly built that weapons which
                degrade the armour of smaller vehicles will not effect it. Because of this, any
                attack that says that the target model is destroyed, wrecked, Explodes! or is
                otherwise removed from play inflicts D3 Hull Points of damage on a Super-heavy
                vehicle instead.

                In addition, any attacks or special abilities that permanently lower the Armour
                Values of a target vehicle do not affect a Super-heavy vehicle. Note that attacks or
                abilities that count the Armour Value as being lower, but do not actually change it,
                work normally.

During deployment, players can declare that any unit that contains at least one model with this special rule is attempting to Outflank the enemy. This means they are making a wide sweeping move to get behind enemy lines or come at the foe from an unexpected direction.

When an Outflanking unit arrives from Reserves, but not Ongoing Reserve, the controlling player rolls a D6: on a 1-2, the unit comes in from the table edge to the left of their controlling player's own table edge; on a 3-4, they come on from the right; on a 5-6, the player can choose left or right. Models move onto the table as described for other Reserves. If such a unit deploys inside a Dedicated Transport, they may Outflank along with their Transport.

In a turn in which a model with this special rule charges into combat, it gains +2 Attacks for charging, rather than +1. A model that has made a disordered charge that turn receives no benefit from Rage.