Two weapon fighting with 4 arms

[Rene Alfonso]

So based on a previous thread discussion this idea cane into play. I was contemplating creating a PC that I lovingly refer to as "the Freak". Essentially I want to mix classes of fighter, ranger, and alchemist to create a 4 armed two weapon fighter. I plan to use the sawtooth saber weapon, one in each of my two hands and use my alchemist levels for defensive buffs like shield or enhancements like expeditious retreat. My first question is in the PHB it says that you do half strength bonus damage with the offhand weapon but strength modifier damage x 1.5 with a one handed weapon wielded two handed. So if I am holding each saber with two arms what is my bonus dabage based on strength? Secondly, I chose the aasimar-Garuda race as my race for this PC. See invisibility once a day is pretty neat. With the build I have in mind what suggestions do any of you have to enhance this build, including suggested archetypes, feats, alternative race, ext. I am open to suggestions. Thanks.

[Durngrun Stonebreaker]

RAW you would not get extra damage. You would be 1x Str on your primary hand and .5x Str on your off-hand. You get 1.5x Str when you use your primary and off hand on one weapon. With two-weapon fighting you use your off-hand for extra attacks.

[Scott Wilhelm]

I don't think it will work. The Vestigial Arm Discovery won't give you extra attacks. And neither do 2 weapon or multi weapon. The Tentacle has an attack, but neither will it give you extra attacks.

But there is a magic item that give you 2 tentacles that do give you an extra tentacle attack, so you should be able to use your alchemal tentacle along with your magic-cloak tentacles as part of your Tentacle attack. And there is no limit to how many Tentacles you can get. Take levels in Monk, Feral Combat Training, and Improved Natural Weapon, and your tentacle attacks will compare favorably with any weapon for damage.

There is a magic mammoth helmet that gives you a Gore attack, there are ways to get bite and claw attacks. If you take Multiattack, you get to use them all, including 1 Monk Unarmed Strike.

There were 2 3.5 races, most notably Thri-Kreen, that had 4 arms and 4 claw attacks. You also could have given them 4 weapons, or 2 double weapons. They had a Racial Weapon called a Gythka, which was a sort of double bastard sword.

There is a Pathfinder Psionic class called the Aegis. They make suits of armor out of psychic energy, and one of the options is 2 extra arms you can wield weapons with.

[Flaming Duck]

Or, since they're both applicable, you could use math...
[TWF/Main hand]*[THF] = 1*1.5*Str = 1.5 * Str for Main Hand
[TWF/Off hand]*THF] = 0.5*1.5*Str = 0.75 * Str for Off-Hand

Reasonable for the feat/class investment, I'd say, and you still get a main attack with 1.5 str. I'd also suggest Power Attack for the off-hand to be 2 for 1 progression, as that's the middle ground for that feat.

Final arbiter is your GM, of course :)