Althor's Arcane Appendage

Background: Althor the One Armed is well known as a master spell creator specializing in force field spells of great elegance and complexity.  He was started down this path when he barely survived a gnoll attack as a young fighter mage (Ax Specialist) by improvising a V only magic missile spell to kill the gnoll that had just ripped off his right arm. He went on to develop a whole class of force field based spells of which perhaps the best known are his Althor's Arm, Althor's Return and Althor's Ax spells.

Casting Restrictions: All of Althor's 4th level spells require at least an 18 INT to learn and cast. All of them are cast as a 4 minute ritual which embeds a spell pattern into the creature or item to be affected or who will be triggering the spell. Once the ritual has been cast the spell can be triggered  as either a reaction or an opportunity action by EITHER a quick 1 hand gesture OR a single keyword as a reaction. If cast as a full ritual (14 minutes cast time) the spell counts as a standard ritual spell. If the shorter ritual is used, then a spell slot is used up. 

Spell: Althor's Arcane Appendage

If cast upon a limb that already has a lower or equal level Althor's Arm or Appendage spell upon it, the lower level spell will be overwritten and replaced with this spell. Attempting to cast a lower level spell on a limb that already has the higher level spell active will fail. 

Althor's Arcane Appendage is a permanent embedded spell and only goes inactive for 1d6 rounds if dispelled just like a normal magical weapon. While in an anti-magic field or the equivalent it is suppressed. A given appendage will also remain if the target shape changes or is polymorphed assuming the shape of the target after the change has a corresponding appendage. So if you cast it on a druid in cat form, any arm or leg appendages would remain when he returned to humanoid form, but a tail appendage would become inactive until the druid took a form with a tail again.

Case 1: Replacing a missing appendage. Creates an invisible appendage at the point the appendage is missing which can be used just as if it were an ordinary appendage for the creature, although the appendage, being force, is immune to normal, non magical conditions such as fires, acid, poison, etc. Also choose one of the following 3 bonuses for the appendage:

a. Appendage holding a weapon or used for unarmed combat: +1 to hit and damage.

b. Appendage holding a shield or parrying weapon or performing an unarmed combat equivalent: +1 AC to attacks that the shield or parrying weapon could be used against.

c. Appendage used for detail work such as lock picking or casting : +1 to Dex or spell mod throws.

Case 2: Overlaying an existing appendage. Creates an invisible sheath of force over one specific appendage which has one of the the following effects chosen at the time of casting:

a. Appendage holding a weapon or used for unarmed combat: +1 to hit and damage. Appendage doesn't touch and is therefore not affected by non magical affects requiring skin contact.

b. Appendage holding a shield or parrying weapon or performing an unarmed combat equivalent: +1 AC to attacks that the shield or parrying weapon could be used against. Appendage doesn't touch and is therefore not affected by non magical affects requiring skin contact.

c. Appendage used for detail work such as lock picking or casting : +1 to Dex or spell mod throws.

Note: Same effects from this spell don't stack as per weaker versions of the spell