As you know, if you have a Soul Weapon, the weapon must strive to become a Deathscythe by acquiring 99 normal tainted souls and 1 witch soul. This can be done with or without a Meister, or a Weapon Technician to wield said weapon. THERE ARE RESTRICTIONS TO BEING WEAPONS, HOWEVER. These might be repeated from the initial rulebook, but they must be stated. Ahem.
1) A weapon cannot be a ninja AND a weapon, just like a Witchling cannot be a Ninja or a Weapon as well, meaning that a Weapon cannot have Jutsu or Magic, though you can post your Soul Energy powers in the Jutsu list... Though there probably won't be a need for many, since you're a weapon yourself. Ah well. Anyway, There will be special cases where a weapon can be a ninja or a witch, as well, but only for SELECT PEOPLE, and there will not be very many of them. Whoever any of the Kages choose that seem to be responsible with such a great task.
2) As stated, a weapon must collect 99 tainted souls and AFTER COLLECTING 99, 1 WITCH SOUL. You cannot get the witch soul first, or achieve 98 or less souls and then get a witch soul and get the rest later. All of your souls will be instantly confiscated and you will go back to 0.
3) Yes, there can be more than one weapon as one person (For example, I'll take a reference from Soul Eater itself, Tsubaki, who was a Ninja Sword, A smoke bomb, a shuriken and a chain scythe) HOWEVER, THIS WILL ALSO BE HEAVILY RESTRICTED. Only certain people will be able to be more than one weapon at once. There will be leniency with 2 or less, however 3 or more will become troublesome, especially if every weapon wants to be more than 2 weapons at once. Most of you will just have to be one weapon and deal with it.
4) Another point of a weapon, let's use Tsubaki again. When she battled her brother, Masamune, she acquired his soul and his weapon form. This can also happen here, HOWEVER, THE WAY FOR THIS TO BE ATTAINED IS THIS; Let's say you're fighting a weapon and you kill the weapon and the soul is right there. You cannot eat it. You must literally absorb it into your own sword and let that person reside there. They will not be dead, for their soul will be living with yours, allowing them to harness their power. It is very hard to kill weapons, so I will say you can absorb as many souls as you want to get however many weapons. Also, to people who think they can have a Soul Absorption ability... No. You can't. You will instantly be labeled as an antagonist and we will smite you. ALSO, to those who think they can kill someone with many different weapons residing with their soul and think they can get them, as well... No. You can't. Once you slay the holder of the souls, the other souls inside of them will become useless as weapons, so you will only achieve the power of the weapon you just slew, not the ones that were residing inside of that one's soul. So ha.
5) Weapons CANNOT DO SOUL RESONANCE, unless they are resonating with others around them in a Chain Resonance or something. Soul Resonance requires a Technician, and NOT ANYONE CAN PICK UP A WEAPON AND SAY THAT THEY RESONATE WITH IT. NO. YOU MUST HAVE SOME TYPE OF COMPATIBILITY WITH YOUR SOUL WAVELENGTHS, But we can get back to that later. As of right now, the powers of a weapon are changing parts of their body, and part of it, into the weapon they are. They can also transfer the power of their soul into their weapon parts and increase power or shoot out soul energies of some kind, I dunno, that's basically up to you... But let me give a reference. Justin Law. He is a guillotine who does not have a partner. He can change his forearm into a guillotine blade and his hands into the guillotine headlock clamps. Also, his attack "Law Abiding Silver Gun" focuses his soul energy into the blade on his forearm and shoots it out as a powerful sharp blast of soul energy. So yes, it is possible. This is how you will fight.
Weapons, abide by these rules, or I will reap your soul. Evilly.