Level 1 Rallying Cry: +1 AB, +20% Movement Speed to all non-hostile creatures within 10m for 1 round (Usable 3x per day).
Heroic Shield: +4 dodge AC to one friendly creature (but not the caster) for one round (Infinite times per day)
Level 2 Inspire courage: +1 AB, +2 vs. mind spells to all non-hostile creatures within 10m for 10 rounds (PDK level/2 uses per day).
Level 3 Fear: Causes all targets in a medium area to become afraid for a number of rounds equal to the caster's character level if they fail a will save vs. fear with a DC of 10 + PDK levels + strength modifier of caster. (Usable once per day)
Level 4 Oath of wrath: +2 to attack, damage, saves, and skills of caster vs. a targeted non-friendly creature's race for a number of rounds equal to twice the PDK level. (Usable once per day).
Level 5 Final stand: 2d10 temporary hit points to a number of non-hostile creatures up to the charisma modifier + PDK level for a number of rounds equal to charisma modifier + PDK level. (Usable once per day).
---No further levels to the class---
Multiclassing tips:
High strength builds may find the fear spell handy when tackling many enemies.
The Purple dragon benefits provide a quick short term boosts to AB which may be quite useful to defensive builds allowing them to go on a short aggressive spree.
Classes with high APR can often make the most of PDK benefits. Though the class is designed much more around aiding a party than going solo.
Disadvantages:
Although this is a party build it does little to help a solo caster's summon at level 40. Besides the +1 AB from inspire courage, it is generally better if the caster concentrates on other things than aiding the summon for a round.
There are very few uses for PDK, especially in higher levels as high level abilities tend to outdo the short less effective buffs.