Build your own impossibly cool weapon [feats] (PEACH)

[DanielLC]

Swordchucks, Yo! [General]
Prerequisites: Dex 15.
Benefits: Attach two weapons together with a rope or chain. You get a -6 penalty for each weapon, or a -4 penalty if the weapon you're not holding onto is light. Using them both is a full-round action. The weapon you're not holding gets an additional -5 penalty if it's a slashing weapon, and cannot be a piercing weapon. When attacking with the weapon you're not holding, if you make a critical failure, you must make a touch attack against yourself. If you succeed, you hit yourself. (There's no good reason that armor doesn't work. I just want it so you need high dexterity to use this weapon without hurting yourself). This feat allows you to use this weapon, but you can never be proficient with it. As such, there will always be an additional -4 penalty.

Normal: If you try to use swordchucks, your DM would get mad at you for referencing 8-bit theater.
Special:This weapon can be used for trip attacks. If it is, that's all it can be used for that round. The weapon you are holding may be a crossbow or a wand. If it's an automatic crossbow, the chain is attached to the lever, so using the second weapon reloads it. Either or both weapons attached together may be double weapons, in which case both sides can be used in that round. If the weapon you are not holding onto is a double weapon, it can't be used on the same enemy twice in one round. You can use this weapon and another weapon in the same round for a -2 penalty to each weapon. This stacks with all other penalties. If you dual wield these, the penalty applies twice. Either of the weapons may be individually magical.

Foo-Bolas [General]:
Benefits: You can connect up to three throwing weapons together with a rope or chain. You get a -4 penalty on each light weapon, and a -6 penalty on each heavy weapon. You get an additional -4 penalty on each weapon if you use three weapons. You get an additional -5 penalty on each slashing weapon. You cannot use piercing weapons.
Normal: You can't.

Double Weapon [General]:
Prerequisites: Base attack bonus +1
Benefits: You can attach any two weapons that aren't double weapons by the handles to make a double weapon. If neither weapon is light, it's treated that way when attacking with both. The non-off-hand weapon may be a crossbow. If at least one of the weapons is a two-handed weapon, you get an additional -4 penalty for that weapon, and a -2 penalty with the other weapon.
Normal: You can only be proficient in normal double weapons.
Special: The non-offhand weapon may be a crossbow or wand.
This is equivalent to simply calling all non-standard double weapons exotic.

One-handed Double Weapon [General]:
Prerequisites: You must be proficient in the double weapon in question.
Benefits: You can use a double weapon in one hand, with a -2 penalty if you only use one side, and a -4 penalty if you use both. This stacks with the -2 penalty for it being a double weapon, giving you a -6 penalty.
Normal: Double weapons require both hands.
Special: You can do two-weapon fighting with this. The penalties stack. This lets you attack up to four times in a round, assuming nothing else applies.

BFS [General]:
Benefits: You can use a weapon one size class larger with a -2 penalty if it's a light weapon (and it's no longer considered a light weapon) and a -4 penalty if it isn't. All other penalties double.
Normal: You can only use a weapon your size.

I'm also thinking of having
Glorius Chainsaw Method [General]:
Make your swords like things unto chainsaws.
Prerequisites: I haven't decided.
Benefits: Your weapons are enhanced with the auras of extraordinary weapons from another world. They get critical hits on a successful touch attack for the next six rounds. This can be used once a day. It takes a full-round action to begin. This is considered a supernatural ability.
Normal: You must make an attack roll to attack, and critical hits aren't guaranteed.
Special: If you're wielding multiple weapons, the duration is divided by the number of weapons. This feat can be taken multiple times. You can use this ability an additional time each day, or double the duration. You can choose which when you use the feat.

Note: none of these feats produce the weapon. They must all be specially made for the sum of the costs of each weapon, plus any extra cost the weapon-smith may ask for for specially making a weapon.

[wadledo]

Already done, a while ago as I recall.

[DanielLC]

All of them?

[Lappy9000]

Why build, when you can duct tape them together?

That link may give you some ideas. Sadly, I'm really not qualified to guestimate the power of these feats.

[theshjuan*]

yeah, i must admit that duct taping weapons together is way cooler.

[Fizban]

I must admit, I have no idea what you mean by the term "use weapon". I would assume you mean to grant an extra attack with the added weapons, but you need to say that specifically. Other times you seem to imply that you're creating double weapons, which means all the feats do is save you a hand for holding the other weapon.

[DanielLC]

I just edited it. I think that clarified it a bit. It's supposed to be that if you use one-handed double weapon and swordchucks, you can attack up to eight times in a round, though only if you're really strong. You should also have to be really dexterous, although I don't know how to make it so you have to be. Perhaps I should add a penalty to AC? I suppose I could say that you have to have light armor.

I just noticed that the penalty for dual-wielding double weapon-chucks is only -6. It looks like I need to edit this again.