So, you may ask, how does one make a whip wielding duelist? When the Whip is a slashing type weapon?
I HAVE FOUND THE ANSWER:
http://www.d20pfsrd.com/magic/all-spells/b/blade-of-bright-victoryI now only need some way to make this permanent without having to take like 11 levels of paladin. I was thinking maybe boosting my UMD to ridiculous levels and getting a wand?
Samsaran Cleric or Oracle with Mystic Past Life to add paladin spells to your class spell list. A cleric would have the spell available at level 5, oracle at level 6.
I think you mean when your whip is piercing, but I digress what Makarion says sounds right to me.
What is it exactly you want to achieve? It does not sound like you are actually trying for the Duelist prestige class, so what other goals do you have for this character build? If it's just a single-onehanded-whip melee combatant you are after, you could look into a bladebound magus using a whip. That would have a similar flavour as the paladin's divine bond.
I don't know of a way to do that without crippling your character. Going duelist is bad enough to begin with (unless you plan on something very specific, such as dervish dancer or a maneuver master build); combining it with a sub-par weapon that doesn't qualify off the shelf is compounding things.
Why not ask permission from your Gm to use a whip, even though it is slashing? Doesn't seem unbalanced to me, and has acceptable flavour I would think.
But what about Duelist makes you want to be one?
The Kensai Magus gets Canny Defense with any weapon (and can be mixed with Bladebound if you want).
You should be able to mix Bladebound and Bladed Scarf Dancer (which also gets Canny Defense) too, and would be similar in concept.
Hmmm, well the Crane style chain will let you parry and riposte, but it is feat intensive. Magus bonus feats can help some.
Human Bladed Scarf Dancer Magus
Str 16, Dex 14, Con 12, Int 15, Wis 10, Cha 7 (20pt buy)
Str 18, Dex 14, Con 12, Int 15, Wis 10, Cha 7 after racial bonus
1st- Dodge
Human bonus- Improved Unarmed Strike
BSD bonus- WF (Bladed Scarf)
3rd-
5th- Crane Style
Magus bonus 5- Crane Wing
7th-
9th- Crane Riposte
11th-
Magus bonus 11-
13-
15-
17-
Magus bonus 17-
19-
Gets Parry (Crane Wing), Riposte (Crane Riposte), and Canny Defense. Uses a whip-like weapon (bladed scarf as one handed weapon).
Might be worthwhile to go Monk (Master of Many Styles) 2 & either Fighter (Lorewarden) or Magus, in that case. You'd have enough feats, for one, and the features you want.
Now I feel I must have missed something, why don't they mix? I don't see any problem.
I do notice I forgot the BAB requirement, but that just pushes the feat back in the progression. So, Crane Wing at 7th, and Crane Riposte at 11th.
Okay, that is not what I thought you meant. You could still be a Magus and use Crane style, its just a choice of tactics from round to round.
And since the ruling that things that are like full-attacks are considered full attacks for effects like Haste (back in Sept.), I don't see a good reason to disallow fighting defensively with Spell Combat.
No, I don't know of a way to let Crane Wing/Riposte work for allies.