Need help creating a spell!

[Podok]

I have an 11th lvl tiefling arcanist who's basically a trickster/thief. I want to make a spell that would allow him to change his shape into a weapon, while retaining his mental faculties. Perhaps the spell could have improvements as you level, such as being able to become special materials or act as a magic weapon or add the flaming property. Ideally, I'd like this spell to last 1 hour per lvl, and I'd like to be able to still sense my surroundings and speak/use telepathy with my wielder. Sound possible? Any ideas on lvl or other restrictions? I'm all ears (or eyes as the case may be). Thanks in advance!

[Azothath]

Requested this thread be moved to the Advice or Homebrew forum.

[Azothath]

Classically you want to find a similar spell and do a variant.
For what you requested, Polymorph Any Object or Shapechange are your similar spells. Sadly they are high level.

A more practical approach is to simply use an illusion and pretend to be what you are supposed to be.

In a low level manner this effect can be accomplished with a sword (bearing your likeness), mage hand, invisibility, and ventriloquism. Enter Image could prove amusing.

[Cevah]

Why become the weapon? Use Possess Object on a weapon. Just need to hide your body.

Or you can use that spell as a basis, and add your senses and telepathy that you want.

/cevah

[Sam Phelan]

Moved to Homebrew

[Goth Guru]

21: Weaponizer
A mutation that lets a character turn into a weapon. They would start with one form, retrainable, and get additional forms as they rise in level. Maybe 3rd level +1 to self or ammo. 5th, can make self or ammo alchemical silver. 7th +2. 9th cold iron. 11th +3. 13th Adamantium. 15th +4. 17th Increased crit range. 19 +5.

The arcana can be aligned(Law, Chaos, Good, or Evil. Smite on crit.) or Elemental damage(Fire, Cold, Acid, Lightning, or Sonic. Burst on crit.)

Aligned would have to be the same as the character(Excaliber is a lawful weapon). Bonus to hit and damage is doubled against opposed alignment.
Elemental damage is 1D6 normally and the mutant has resistance equal to the bonus.

They can take special abilities as feats. These include bleed, envenoming(possibly with holy water), exploding ammo, ghost touch, ect.

This is a mutation.
Go to Leveled Mutations.

Perhaps the character was mutated while researching the spell at too low a spell level. If it seems too powerful, try adding more defects, such as all gear falling off whenever they transform. Maybe they are vulnerable to anything that effects both people and objects in both forms. ect...