Ok so Multiweapon Fighting allows beings with 3 or more arms to use their primary hand and extra arms as off-hand attacks.
So lets take the Kasatha which has 4 arms in total granting a total of 4 attacks.
Now which is more beneficial to use Multiweapon Fighting or Flurry of Blows.
For this lets only use Unarmed Strike as the weapon used with both.
So say you have a +10 to hit via BAB and Str(or Dex) with Multiweapon you take a -2 on all attacks to attack a total of 4 times in that round.
Lets say this is Level 8 (For a 3/4 BAB class this is when they get their second iterative attack.)
So wouldn't the Multiarm fighter have a total of 8 attacks, 4 from the first bonus, and 4 from the second.
Where as a Monk with Flurry at level 8 has 4 with a total bonus of +6/+6/+1/+1 But I believe these bonuses are stacked onto the +10 meaning more likely to hit? Or is that wrong?
In general if you are playing a Kasatha should you be using Multiweapon Fighting over Flurry for more attacks and more damage?
Sadly, from all the posts that I've seen, Flurry of Blows is a completely seporate ability than the ACTUAL Two-Weapon fighting feat... It ACTS like it, but is not it. So in the beginning, It would be better to have Multiweapon Fighting, as you would get 4 attacks. But later, as Monk gets more attacks at a better progression, that is actually better...
What I'm currently looking into is a similar build with Brawler as they actually get the Two-Weapon progression as well... But my DM has allowed D&D 3.5 content, so that allows me to use the Multiweapon Fighting progression... But that's house rules, not OFFICIAL Pathfinder.
I believe if you had a brawler with 4 arms, or a fighter that has a high attack progression and the Two Weapon fighting progression, you would still be able to make 2 attacks (total, 1 for your last 2 arms each) at the end of your attacks...
Assuming that the two do not mix, flurry of blows might end up being better depending on the build due to a number of factors...
But if we are only talking about unarmed strikes, then multiweapon fighting beats out flurry.
Flurry of blows shines with two advantages that are not involved with unarmed builds:
1.) It gets full power attack with each hit. Decent enough when compared to normal TWF builds, but not so much when compared to the 2 extra hits (at each iterative with your house rules) found with multiweapon fighting. Flurry can beat out MWF if 2 handed weapons are used, since each attack gets 1.5x power attack.
2.) Enhancements- This doesn't matter if we are talking about the whole body enhancement with AoMF, but with regular weapons, flurry of blows wins out most of the time. One of the weaknesses of TWF is that it is pricey: you need to maintain 2 weapons. MWF is even more pricey. Meanwhile, flurry of blows can be done with one weapon, which means that you can invest more into it, ergo better damage and accuracy.
Flurr of blows ends up winning because it doesn't require high dex and feat taxes while ending up with almost the same DPR.
Eh, not that high a dex. It helps that Kasathas have +2 dex/+2 wis with no penalty.
Now, lets assume you are something other than a monk for this (since it would just be a liability for multiweapon fighting qualifications). So lets say Fighter (just for DPR). Overall, I am aiming for a class without too much need for mentals stats. Cavalier works too. Ranger and Slayer...don't get into this problem
So, assuming a 20 point buy, you can get away with these stats
STR: 16 DEX: 16 (14) CON: 14 INT:10 WIS: 12 (10) CHA: 10
Maybe WIS: 14 (12) CHA: 8
Throw in your 4th level ability score adjustment, and you have everything you need to pick up the good TWF feats. The only one that needs 19 DEX is Greater TWF... which is an attack that hits at BAB-12. Not the best investment. So there are only about... 3 'must have' TWF feats then: TWF (MWF), ITWF, and two weapon rend. Double slice is kind of overrated, since it only adds 1/2 your str to offhand attacks (might be better with this MWF thing... still).
But then again, you can probably use it as a tool to trade out flurry for something else and still have a cool full-round attack option.
A master of many styles Kasatha, for example, could pobably be about as powerful as a regular monk.