Bishops are the specialized healers in Lineage 2. They are the only class which gets the uber healing spells Greater Battle Heal and Restore Life, and they get the powerful Mass Resurrection. They also can solo undead non-group mobs quite easily.

Key Skills

Healing

Greater Heal - Improved version of Heal. (40+3)
Greater Battle Heal – Improved version of Battle Heal. (40+3)
Greater Group Heal – Improved version of Group Heal. (40+3)
Greater Resurrection (3) – Resurrects another character from dead, restores up to 70% of xp. (?/?/40)
Mass Resurrection – Resurrects every dead clan/alliance member in a very short range. (40)

(this skill is currently bugged if you use it, do not have anything targeted)

Purify – Heals paralysis and removes bleed and poison.
Restore Life – Heals a percentage of HP.

Attacks

Hold Undead – Paralizes an undead mob for a few minutes.
Might of Heaven – Damage against an undead mob.
Peace - Puts opponent's mind at peace. Desire to attack is decreased.
Requiem – Disables preemptive attacks from undead mobs in a fixed range.
Repose – Disables undead mobs will to attack in a fixed range.
Sleep – Puts a target into a state of sleep.

Equipment/Playstyle

Bishops get the skill to wear both robes and light armor. Like all clerical classes, they get a generic weapon skill that allows to use all weapons equally well. While battling undead with their spells, they will prefer weapons with high matk. Otherwise, they have little use for it. Still wizard weapons are a good choice for bishops on high levels as they can have special abilities like Mana Up or Acumen.