ZARATHOS, M CE HUMAN CLERIC 16 / BLACKGUARD 3 / WARPRIEST 1
The concept behind this Cleric build is simple yet very effective. He combines both damage casting and front-line fighting capability. The build focuses almost exclusively on the acquisition of Cleric levels and spell power, but with just a few levels from certain prestige classes to enhance both melee and spellcasting power at the same time.
My domain choices were Water and Air. Water allows the use of Ice Storm as an offensive spell, as well as the Evasion ability that would normally be restricted to Rogues and Monks and the like. Air allows the casting of Call Lightning and Chain Lightning as damaging spells.
One level of War Priest allows this character to equip Tower Shields and Martial Weapons, and also bestows the War Glory aura that will impose a -1 saving throw penalty on all enemies within a 10' radius.
Two levels in Blackguard provide the Dark Blessing power, which provides a bonus to saving throws based on the Charisma bonus modifier that parallels the Paladin's Divine Grace power.
A third level in Blackguard provides the Aura of Despair power, which inflicts another -2 saving throw penalty on all enemies within a 10' radius. It also stacks with the War Glory aura.
The net result is a character who can mix it up in melee, but can also cast powerful offensive spells that his enemies are highly unlikely to resist due to the cumulative effect of his auras. The auras not only benefit the character when he casts his own spells, but will also benefit companion spellcasters (e.g. Qara and later Safiya) when they aim offensive spells at enemies near him.
Another key part of the build is the Persistent Spell feat. The feat allows the character to cast buff spells that will last without any lapse until the character rests up, so long as the character is willing to memorize that buff at six spell-levels higher. In particular, a Persistent Divine Favor will grant a day-long +3 attack bonus and +3 magic damage on physical attacks. A Persistent Prayer spell will provide all allies with a +1 bonus to both attack bonus and saving throws, and a -1 penalty to all enemies within sight to attack bonus and saving throws. The saving throw penalty will also stack against any enemies within 10' of the character's other auras.
Stats
It's Wisdom all the way because it enhances the number of Cleric spells he can prepare, and the saving throw Difficulty Class of his spells.
Skills
I spend the early levels obtaining the prerequisites for the prestige classes. That means 8 ranks in Diplomacy, 5 ranks in Spot, and 5 ranks in Hide.
Next, I invest skill points into Use Magic Device, at least when I'm not taking any Blackguard levels. My goal is 10 skill ranks in Use Magic Device, which will be raised to 15 after the Charisma bonus modifer (helped along by a Nymph Cloak +8). The idea is to be able to export Boots of the Sun Soul +5 into Mask of the Betrayer.
I am doing all of this without the benefit of the Able Learner feat, which admittedly does make this build awkward to get off the ground. But it is worth it.
Intimidate is going to be this character's main conversational skill. But I only obtain ranks in Intimidation whenever I take a Blackguard level, the reason being that Intimidate is a class skill for the Blackguard (i.e. only costs 1 skill point to advance a rank). You'll notice that I inserted a Cleric level in between the 2nd and 3rd levels of Blackguard. The reason being to ensure that I can be cost effective about acquiring skill ranks in Intimidate (i.e. I don't have to expend 2 skill points to advance in another rank in Intimidate were I unable to use up all my skill points during a Blackguard level-up). The end result will be 16 skill ranks in Intimidate, helped along by the character's Charisma bonus modifier.
Once all of that is taken care of, I now pour all my skill points into Spellcraft until it is maximized. The reason for that is to make sure my Spellcraft skill rank is up to speed when I want to acquire the epic spells during Mask of the Betrayer.
After that, I go with +1 Spellcraft and +3 Concentration during each level-up, so that the latter begins to catch up as well.
Feats
Starting Feats (Cleric 1): Spellcasting Prodigy - The feat of choice whenever you make a damage caster build. It's like getting all of the Spell Focus feats for all spell schools at once, as long as you take it when it's available only at 1st level.
Power Attack - A prerequisite for Cleave.
2nd level (Cleric 2): No feat selected.
3rd level (Cleric 3): Cleave - Extra attacks are always nice, but it's also a prerequisite to the Blackguard prestige class.
4th level (Cleric 4): No feat selected.
5th level (Cleric 5): No feat selected.
6th level (Cleric 6): Combat Casting - A prerequisite for taking one level in War Priest.
7th level (Cleric 7): No feat selected.
8th level (Warpriest 1): War Glory - Automatically obtained upon taking a single level in Warpriest. It imposes a -1 penalty on both attack bonus and saving throws for all enemies within 10 feet. It will stack with the Blackguard's Aura of Despair and other abilities that impose saving throw penalties.
Weapon Proficiency (Martial) - Automatically obtained upon taking a single level in Warpriest. Its ultimate significance is that it will allow Zarathos to wield a custom-made Warhammer during the Mask of the Betrayer expansion.
Tower Shield Proficiency - Automatically obtained upon taking a single level in Warpriest. It allows Zarathos to use the Forgotten Shield during the OC, and continue to use it during the Mask of the Betrayer expansion.
9th level (Blackguard 1): Practiced Spellcaster - This feat raises Zarathos' effective caster level by three, as though his Warpriest and Blackguard levels contributed to the damage and duration of his spells. The spell itself can raise maximum caster level by four. I'll explain it this way. Let's suppose a character has 5 levels of Wizard and 4 levels of Fighter. If he were to cast a Fireball without the benefit of the Practiced Spellcaster feat, it would only score 5d6 fire damage on its targets. With the feat, the Fireball would instead inflict the full 9d6 fire damage on its targets. It also increases the temporal duration of the character's spells, as though the character had more caster levels (to a maximum of four).
10th level (Blackguard 2): Dark Blessing - Allows a Blackguard to add his Charisma bonus modifier as a bonus to his saving throws, making the Blackguard the evil equivalent of a Paladin.
11th level (Cleric 8): No feat selected.
12th level (Blackguard 3): Aura of Despair - Automatically obtained on attaining the third level in Blackguard. It imposes a -2 saving throw penalty on all enemies within a 10' radius of Zarathos, and it will stack with his War Glory aura as well. That will mean that his spells like Chain Lightning and Hammer of the Gods and Storm of Vengeance are very likely to have full effect on enemies that surround him. Furthermore, the saving throw penalties will also apply when an allied spellcaster like Qara or Safiya cast spells on enemies that surround him.
Empower Spell - Will increase the damage by x1.5 of spells like Call Lightning and Hammer of the Gods and Ice Storm, as long as Zarathos memorizes them at 2 spell levels higher.
13th level (Cleric 9): No feat selected.
14th level (Cleric 10): No feat selected.
15th level (Cleric 11): Extend Spell - Will double the duration of buffs such as Battletide and Divine Power, as long as he memorizes them at 1 spell level higher. It is also a prerequisite for the next feat.
16th level (Cleric 12): No feat selected.
17th level (Cleric 13): No feat selected.
18th level (Cleric 14): Persistent Spell - The point of this spell is that it allows Zarathos to apply some really useful buffs that would otherwise have short durations, but will now last until Zarathos gets around to resting. See my comments below for specific applications of this feat.
19th level (Cleric 15): No feat selected.
20th level (Cleric 16): No feat selected.
Inventory
Keep in mind that I discuss the equipment each character has at the end of the OC and won't get into interim equipment, although I sometimes do discuss interim equipment during the main walkthrough itself.