I think this is a very interesting start, alex. I have to admit to liking it quite a bit, but that may be because some options seem pretty strong . . . . Maybe some more clarification from you would help.
1) Smite -- You did intend for the deflection bonus to AC to be absent, correct? As in: this is not quite as strong as the core paladin's smite ability (which I think is a solid balancing effect on the build).
2) Surge of Strength -- How many times per day can this ability be used? Are you going to model it after the paladin's lay on hands ability in terms of frequency?
3) Divine Gift -- This is the one that needs the most explanation, I think. First of all, at what caster level would the chosen spell function? Would that caster level change as the character gained HD, or as level advancement granted additional instances of 'Divine Gift'?
4) Enhanced Smite -- Is this increased damage only effective on the first successful attack per smite use, or per round? If combined with bull rush, trip, or sunder, are the smite bonuses granted to the CMB roll and the damage applied as a bonus to the result of the maneuver? Or is the bull rush/trip/sunder attempt added to the normal mechanics of the smite weapon attack?
5) Divine Strike -- Tying this ability to the Weapon Focus feat may be too restrictive, especially since the ability in question grants modifiers very similar to those of the core fighter's weapon training ability. It may reward weapon diversification a bit too strongly, as well -- a crusader that has Weapon Focus (greatsword) and Weapon Focus (composite longbow) would, apparently, benefit from Divine Strike at the full rate (+4 at 17th level). That benefit at the cost of two feats may be too strong. All that being said, the Divine Strike progression being enabled for one weapon group may be sufficient.
6) Aura of Resilience -- Does the aura grant the +4 bonus to saves vs ability drain and level drain, in addition to the saves vs fatigue and exhaustion?
7) Aura of Wrath -- This may be only a localized effect, limited to a 10-foot range, but this is still Weapon Specialization, and effectively "always on". I think this is too much. However, I think a reactive boon may still be the right path; more on that later.
8) Paragon -- What type of bonus is the +4 to Str or Cha?
If we take your crusader class as you have first presented it, and make a straight comparison to the paladin and the fighter at equivalent levels, I think we'll begin to see where you have too much in place.
If we begin with these given factors:
- Strength of 16 at 1st level
- All ability score increases invested in Strength
- Charisma of 14 at 1st level
- +6 enhancement items for both Strength and Charisma
- Wealth by level dedicated to maximizing attack bonuses
Crusader 20 Smite attack bonus: +47
Paladin 20 Smite attack bonus: +41
Fighter 20 attack bonus: +40
None of this accounts for feats, ioun stones, spell effects, etc., but only makes use of elements of the "Big Six" and class abilities as presented in the Core Rulebook and your initial post. Those additional elements would aid the fighter most in bridging the gap, but the crusader would still hold a phenomenal advantage.
Even with this cursory examination, such as it is, I think your initial build is too strong. The crusader would make the paladin and the fighter both undesirable for DPR players, in particular.
EDIT: Since the Paragon +4 bonus would be inherent, that does a great deal to nix my attack bonus calculations, but still only adjusts the crusader's final bonus to +45. I originally included a +5 inherent bonus in the calculations to indicate each character's use of a +5 tome.
More later tonight or tomorrow, man! Keep brainstorming!! :)
I clicked on this because it said paladin/fighter hybrid. I don't see any fighter in this. This is a paladin variant with less of an alignment restriction.
You condition on which Smite is allowed to activate is vague. I suggest making it more like the paladin's smite ability.
I don't think that Divine Strike is neccessary, especially if Syrus's calculations are correct. If you want this to be a fighter hybrid, I suggest replacing Divine Strike with a series of bonus combat feats, perhaps ones that allow him to use his level as his fighter level? maybe at levels 2, 6, 10, 14, and 18.
I suggest scrapping Divine Gift as written, and replacing it with a series of abilities/exploits/talents that are unique to this class. Maybe at levels 4, 8, 12, 16, and 20. The ability to get a permanent 1st level spell has not been thought out. Some would be just too good. Divine Favor is way to easy a choice for +3 to all attack and damage rolls by level 9, and Grace would deny all attacks of opportunity for movement.
@Ciaran --
The strongest fighter element present in this build is Divine Strike: it is, effectively, weapon training.
@alex --
1) I think you should choose either the smite ability or the Divine Strike, but not both.
2a) If you choose smite, I would change it to 1/day gained at 1st, 5th, 10th, 15th, and 20th, to a maximum of 5/day, and let it function fully as the paladin's smite (bonus to attack, damage, and deflection AC vs the target.
2b) If you choose Divine Strike, the attack/damage bonuses should scale as you have them listed, but should only apply to a deity's favored weapon or an alignment weapon (along the lines of the description in spiritual weapon). Furthermore, the instances at 9th, 13th, and 17th could unlock weapon talents from the fighter class.
3) I think Divine Bond should be dropped. It's "too much paladin".
4) I believe that each instance of Divine Gift and the Enhanced Smite and Greater Smite should be replaced with fighter bonus feats and/or a scaling progression of the crusader's auras. For instance, boosting the range of the aura to a 20-foot radius at level 12 does not seem to be "too much" to me; it further distances the class from both source classes and leverages one of the more original features you've developed.
5) But that means I need to skip ahead a bit -- the 20th level Paragon ability should not provide an inherent ability score bonus. Rather, this should be the point at which the crusader gains the ability to project auras at a range of 30 feet. I think the auras are the strongest element of this class, so making the capstone ability tie in with them is a "must", I think. But I don't know what else to add to that range bonus, because we definitely need something more here . . . .
6) Surge of Strength should be "self only" -- allies already get a ton of benefits from a crusader.
7) Aura of Faith has some unnecessary overlap with Divine Strike -- if your weapons already count as good-aligned, why make an aura for it, too?
I would try to hammer out more things to help, but I've got a full day at work today. Busybusybusy.
Keep at it, chief!
Hybrid classes are such a tightrope... I think this kind of idea is best handled with a fighter archetype - which is kind of what a Paladin is anyway...