The mercenary (base class)

[Ziegander]

There's a lot of interesting stuff in here, but the bonuses to AC, attack, and damage are staggeringly unnecessary. +21 to AC, +30 to attack and damage as well as -1 to +3 damage ratio with two handed weapons. Sneak Attack +6d6 (average +21 damage) as well as Smite 6/encounter (+Cha mod to hit, +20 to damage).

At 10th level, for example, he doesn't even have dance of blades yet, but he does have two longswords that give him +5 deflection and a +5 shield bonus to AC, +5 to attack and damage rolls with them (on top of full BAB), and three attacks. If he's got a Strength score of 22, which isn't unreasonable, and let's give him a pair of +1 longswords, his attack routine is +22/+22/+17 for 1d8+12 damage on each hit and his AC in a +1 Chain Shirt, with Dexterity 16, is 29. If he sneak attacks and smites, let's give him a Charisma of 14, his attack bonus goes up to +24 and his damage increases by roughly 20. Against a Fire Giant, a CR 10 foe with solid hp and AC, he can only miss on a roll of 1 for his first two attacks, or on a 5 or lower with his third. With no sneak attack or smite his average damage per round on that guy, without power attacking is roughly 44, meanwhile the Giant has trouble hitting the mercenary, hitting with his first attack on an 9 or higher, his second on a 14 or higher, and his third on an 19 or higher. The Fire Giant only manages (again, with no power attack) a DPR against the mercenary of 30. If the mercenary manages to sneak attack, his DPR goes up by roughly 27. If he chooses to smite with abandon, his DPR increases by another 27. Without any extra bonuses from gear or feats, the mercenary can very easily deal anywhere from 50% to 70% of a Fire Giant's health on his first turn of combat. He can power attack at a -1 to +2 damage ratio with both of his longswords anytime he wants, thanks to his Two-Handed Fighting Style, so when he's smiting, he can easily just turn 2 points of superfluous attack bonus for his first two attacks (since he hits on a 2 even without the smite attack bonus) into 8 additional points of damage. That's a 100+ damage alpha strike for a 10th level character with no optimization at all, able to trivialize what is generally a difficult encounter even for a class like a Crusader or Warblade.

Put simply, this class has way too many numerical bonuses. They are nearly absurd and take the place of interesting class features. Tone a lot of those bonuses down (+ half level, + level, these sorts of bonuses are usually not necessary if they are constant effects), and replace them with interesting new things to actively do.