The UberTripper (help needed)

[Ohiohi]

I want to make a fighter that mixes the standard Ubercharger build with some tripping/BFC, to not being destroyed after a shock trooper charge, when I found this feat:Mercurial Strike (http://dndtools.eu/feats/dragon-compendium--109/mercurial-strike--3374/).
So I thought "Let's add some Iaijutsu!!!!"
Is there a way the playground can get:
-Ubercharger
-Tripper
-Iaijutsu Mercurial Strike
On the same build?
Maybe I can also get Knock-Down (http://dndtools.eu/feats/sword-and-fist-a-guidebook-to-monks-and-fighters--50/knock-down--3189/) allowed from my dm, for some extra goodies!

My thoughts were on something like Spirit Lion Totem Barbarian 1/Factotum 1(for Iaijutsu)/Fighter X

[Rebel7284]

Mercurial Strike makes it harder to use a reach weapons as you have to be unarmed until provoked. Thus I feel it's a bad feat for a tripper build.

[Extra Anchovies]

Do whatever you can to get Knock-Down permitted. A Knock-Down/Improved Trip build can essentially triple the number of attacks it gets (attack -> free trip -> free attack) by level three without an ounce of cheese. It's the feat that lets trippers keep up with überchargers.

[eggynack]

You should definitely add a second level of barbarian. Doing so grants access to wolf totem (http://www.d20srd.org/srd/variant/classes/variantCharacterClasses.htm#wolfTotemClassFeatures ), which gives you improved trip without the annoying combat expertise prerequisite. A single level for two feats, in other words. Also worth picking up, though less critical, is whirling frenzy (http://www.d20srd.org/srd/variant/classes/classFeatureVariants.htm#rageVariantWhirlingFrenzy ). Great stuff, that.

[Vogonjeltz]

Hold the Line, enemies provoke an AoO by moving into a square you threaten. Bear in mind, unarmed characters don't threaten any squares, so you would need to pick up Improved Unarmed Strike to actually threaten an AoO. Without that, Mercurial Strike technically does nothing, because unarmed characters threaten no squares.

[Oddman80]

Hold the Line, enemies provoke an AoO by moving into a square you threaten. Bear in mind, unarmed characters don't threaten any squares, so you would need to pick up Improved Unarmed Strike to actually threaten an AoO. Without that, Mercurial Strike technically does nothing, because unarmed characters threaten no squares.

or he could just have a spiked gauntlet... which is advisable anyway if he is planing on tripping with a polearm.

[Oddman80]

So this might not fly with your DM, but what about...

Human Barbarian w/ 2 Flaws.
Flaw 1 Feat - Improved Bull Rush
Flaw 2 Feat - Power Attack
Human Feat - Combat Reflexes

Weapons - Guisarme with Spiked Guantlet

Level 1 - Whirling Frenzy, Lion Spirit Totem Barbarian (Gain Pounce)

Level 1 Feat - Extra Rage
Level 2 - Wolf Totem Barbarian (Gain Improved Trip)
Level 3 - Fighter

Fighter Bonus Feat - Knock-Down
Level 3 Feat - Combat Expertise
Level 4 - Fighter

Fighter Bonus Feat - Dodge
Level 5 - Feat Rogue

Feat Rogue Bonus Feat - Karmic Strike
Level 6 - Feat Rogue

Level 6 Feat - Shock Trooper
Feat Rogue Bonus Feat - Cleave

[Vogonjeltz]

or he could just have a spiked gauntlet... which is advisable anyway if he is planing on tripping with a polearm.

Hrm, I suppose the spiked gauntlet does only say the character is considered armed, so that they are really still unarmed. So yes, that should work. The feat really should simply specify that it works despite the character not actually threatening those squares, because that seems to be what is intended.