It also makes absolutely no sense for a Kensai to be able to add enhancement bonuses in addition to the weapons normal bonus.
Its
explicitly allowed by the class- see the example listed under the chart where it mentions a Kensai enhancing a magical weapon, and the wording "the weapon becomes magical, if it wasn't already" (I'm paraphrasing- I don't have the book in front of me at the moment).
Finally, the words "can place" don't imply addition, they just say that it's possible to do so. I can place an entire gallon of milk into a gallon-sized jug of milk. Of course, if the jug is already half full, I can't...
The limit would remain at +10 overall, no matter the level of the kensai.
In your analogy, you're assuming that a 3rd level kensai can only fill a jug up to 3 gallons. The way I'm interpreting the language, a kensai can fill a milk jug (enhance his signature weapon) up to his level, so long as he does not exceed the game limit- but the limit here is 10 gallons. As long as the weapon he holds in his hand as his signature weapon isn't already enhanced to more than "7 gallons," the 3rd level kensai can freely add up to his level.
IOW, what we're arguing about is the size of the jug. You say its 3gal for the 3rd level Kensai, I say its 10gal.
A Kensai can place a certain enhancement into his signature weapon - a certain total.
Dictated by his level- nothing in the text says he can't add his max level to the weapon.
...it'd be attractive for a kensai to "lose" his weapon (since improving an already enhanced weapon will be expensive) occaisionally and buy a more buff one, and then further pimp it. That, of course, is completely contrary to the entire class concept.
Attractive? I don't think so- that would be dishonorable, contrary to his vows and inherently chaotic, and thus, not seriously contemplated...and as a DM, I'd probably disallow it.
Furthermore, the actual example of a kensai improving a weapon which is already magical says "if a kensai has a +1 longsword and wants to imbue it with the power to be a +3 longsword," which clearly focuses on the power the kensai is imbuing to become in total, not the increment.
As I pointed out, we don't know if the kensai in question is 2nd level or 8th, so we don't know the nature of the limitation.
Perhaps he only has the levels to make it a +3 weapon, perhaps he has more levels and wants to add abilities other than plusses. The class has no way to alter the enhancements to the weapon- once in place, they remain in place, unchangeable. A higher level kensai might choose to enhance a weapon to +3 and no further because he's planning to add a +3 equivalent special ability.
In any case, this does not pertain to the monk issue - any number of other classes can become a kensai; the PrC is not specifically for monks.
True, but it
is on the short list of PrCls which Samurai, Paladins and Monks can take and still multiclass- all of the others (AFAIK) that let a monk do so are Monk PrCls- close enough for me.
And your build still doesn't use any of the monk's key features. Sure, it "can" use unarmed attacks, but you've indeed not chosen to make them your signature weapon, and you're a really low level monk, so your unarmed attacks deal virtually no damage - certainly, they can't even come close to your signature weapon.
It can, and in fact, often has to use unarmed attacks if the foes close to within the effective threatened area of the reach weapon because once the monk starts increasing his reach & damage by increasing his size (by whatever means), that area within the polearm's killzone becomes larger, making unarmed combat skill that much more important. And, of course, the unarmed damage goes up as well...
You still haven't demonstrated a dex-based monk, in other words.
Yes I have- I've demonstrated that you
don't build them like Str Monks- if you do, they'll pale in comparison
every time. Instead of trying to meet force with lesser force, you concentrate on what they do better.
1) Dex monks use ranged weapons more than the Str monk
by design. Hitting your foes with something (manufactured weapon, alchemical weapon, etc.) before they close is a good, effective tactic, and could turn the tide of battle.
2) You use a reach weapon to improve the likelyhood of using your AoOs to maximum potential. Without a reach weapon, its entirely likely that most of your AoOs will go unused as foes simply pass you by (but for the one or two who actually engage you) as they prioritize spellcasters and tanks. Most of those potential AoOs you're trying to purchase with a high dex and Combat Reflexes simply won't materialize.
With a reach weapon and the right feat selection- Combat Reflexes, Hold the Line, Stand Still, Deft Opportunist, etc.- the Dex monk maximizes his chances of getting all of his AoOs in and making them useful, stacking up more attacks at his highest BAB than the Str monk will.
Furthermore, by threatening a larger area, you're (potentially) granting more of your allies flanking bonuses.
3) If your monk is stuck in the second rank behind a wall of tanks, using ranged and reach weapons- 2 areas where the dex monk excels- allows you to continue to contribute effectively even though you're not on the front line.
The Githzerai monk used a 3rd party monk PrCl, yes, but in terms of what it granted for the dex build, it was no different than the Fist of Zuoken or the Zerth Cenobite by WotC. All allow the monk to use psionic abilities from the PsyWar list, meaning the monk would have Expansion, letting him go from Medium to Large and eventually to Huge.
The feat selection was nearly identical to the Kensai, with one exception being Pole Fighter (from DCv1) which allows the monk to use a polarm as a monk weapon. Where the Kensai gains damage output from enhancing the weapon, the Githzerai build boosts its output with FoB and the like. But since Pole Fighter is technically a 3rd party feat (despite that "100% Official" text above the magazine's title), some wouldn't want me to post that build here.