Chaplain Grimaldus

Friendly Black Templars units within 6" of Chaplain Grimaldus have the Zealot special rule.

When choosing an army, all models in the same Detachment or Formation must be drawn from the same Chapter.  If a unit's datasheet contains a Chapter in brackets after the Chapter Tactics special rule - for example, "Chapter Tactics (Ultramarines)" - the unit must always be drawn from this Chapter, and therefore cannot be included in a Detachment or Formation with any units that are drawn from other Chapters. All models drawn from a given Chapter benefit from that Chapter's Special Rule. If a unit contains models drawn from two different Chapters, it counts as from neither Chapter, and thus benefits from neither Chapter Tactic.

Independent characters can join other units.  They cannot, however, join units that contain vehicles or Monstrous Creatures.  They can join other Independent Characters, though, to form a powerful multi-character unit!  Independent Characters pass Look Out, Sir rolls on a 2+. A unit that contains one or more Independent Characters does not need a double 1 to Regroup if reduced to below 25% of its starting numbres, but instead tests as if it had at least 25% remaining.

Full details in BRB. Rule too long to copy verbatim.

A unit containing one or more models with the Zealot special rule automatically passes Pinning, Fear and 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 gains the Zealot special rule when it has Gone to Ground, all the effects of Go to Ground are immediately cancelled.

In addition, units containing one or more models with the Zealot special rule re-roll all failed To Hit rolls during the first round of each close combat - they do not get to re-roll failed To Hit rolls in subsequent rounds.

At the end of each of your turns, roll a D6 for each of your models with this special rule that has less than its starting number of Wounds or Hull Points, but has not been removed as a casualty or destroyed. On a 5+, that model regains a Wound or Hull Point lost earlier in the game.