Uriah Jacobus, Protector of the Faith

Once per game, Uriah Jacobus' unit can attempt to use a bonus Act of Faith, even if his unit has already used all its Acts of Faith. The Leadership test for this bonus Act of Faith is automatically passed and the unit's Act of Faith resolves as per its Army List entry. Only the unit's Act of Faith can be used in this way, not that of any Independent Characters that have joined the unit. Uriah Jacobus can use this bonus Act of Faith even if his unit contained a model with a Simulacrum Imperialis that has been removed as a casualty. Using Uriah Jacobus' bonus Act of Faith does not prevent his unit from attempting to use any remaining Acts of Faith it has in subsequent phases.

The Warlord, and all models in the Warlord's unit that have the Shield of Faith special rule, have a 5+ Invulnerable save.

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.

Models with the Shield of Faith special rule have a 6+ invulnerable save and the Adamantium Will special rule.

If a model with the Martyrdom special rule is your Warlord, and that model is removed as a casualty during the battle, all friendly units wholly comprised of models with the Act of Faith special rule automatically pass all Leadership tests until the end of your next turn.

A model with this special rule can take a Leadership test at the beginning of each Fight sub-phase in which he is locked in combat. If the test is successful, choose one of the following war hymns to immediately take effect.

The Emperor Protects: The model and his unit re-roll all failed armour and invulnerable saves until the end of the phase.

The Emperor's Strength: The model has the Smash special rule until the end of the phase.

The Righteousness of the Emperor: The model and his unit re-roll failed rolls To Wound until the end of the phase.

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.