A while back, I wished to play a Soul Knife in a magic only campaign. These are the mods I made and the GM was satisfied. Hope it's of benefit.
Hit Die d10.
Class Skills The soulknife’s class skills (and the key ability for each skill) are:
Climb (Str), Craft (Int), Hide (Dex), Jump (Str), Knowledge (arcana) (Int),
Listen (Wis), Move Silently (Dex), Profession (Wis), Spot (Wis), and Tumble (Dex).
Skill Points at 1st Level (4 + Int modifier) ×4.
Skill Points at Each Additional Level 4 + Int modifier.
All the following are class features of the soulknife.
Weapon and Armor Proficiency
Soulknives are proficient with all simple weapons, with their own mind blades, and with light armor and shields (except tower shields).
Mind Blade (Su)
As a move action, a soulknife can create a semisolid blade composed of magical energy.
The blade is identical in all ways (except visually) to a short sword of a size appropriate for its wielder.
For instance, a Medium soulknife materializes a Medium mind blade that he can wield as a light weapon, and the blade deals 1d6 points of damage (crit 19-20/×2).
Soulknives who are smaller or larger than Medium create mind blades identical to short swords appropriate for their size, with a corresponding change to the blade’s damage.
The wielder of a mind blade gains the usual benefits to his attack roll and damage roll from a high Strength bonus.
The blade can be broken (it has hardness 10 and 10 hit points); however, a soulknife can simply create another on his next move action.
The moment he relinquishes his grip on his blade, it dissipates (unless he intends to throw it; see below).
A mind blade is considered a magic weapon for the purpose of overcoming damage reduction.
A soulknife can use feats such as Power Attack or Combat Expertise in conjunction with the mind blade just as if it were a normal weapon.
He can also choose mind blade for feats requiring a specific weapon choice, such as Weapon Specialization.
Spells that upgrade weapons can be used on a mind blade.
A soulknife’s mind blade improves as the character gains higher levels.
At 4th level and every four levels thereafter, the mind blade gains a cumulative +1 enhancement bonus on attack rolls and damage rolls (+2 at 8th level, +3 at 12th level, +4 at 16th level, and +5 at 20th level).
Even in places where magical effects do not normally function (such as within a anti-magic field), a soulknife can attempt to sustain his mind blade by making a DC 20 Will save.
On a successful save, the soulknife maintains his mind blade for a number of rounds equal to his class level before he needs to check again.
On an unsuccessful attempt, the mind blade vanishes.
As a move action on his turn, the soulknife can attempt a new Will save to rematerialize his mind blade while he remains within the magic negating effect.
Weapon Focus (Mind Blade)
A soulknife gains Weapon Focus (mind blade) as a bonus feat.
Throw Mind Blade (Ex)
A soul knife of 2nd level or higher can throw his mind blade as a ranged weapon with a range increment of 30 feet.
Whether or not the attack hits, a thrown mind blade then dissipates.
A soulknife of 3rd level or higher can make a eldritch strike (see below) with a thrown mind blade and can use the blade in conjunction with other special abilities (such as Knife to the Soul; see below).
Eldritch Strike (Su)
As a move action, a soulknife of 3rd level or higher can imbue his mind blade with destructive magical energy.
This effect deals an extra 1d8 points of damage to the next living, non-mindless target he successfully hits with a melee attack (or ranged attack, if he is using the throw mind blade ability).
Creatures immune to mind-affecting effects are immune to eldritch strike damage.
(Unlike the rogue’s sneak attack, the eldritch strike is not precision damage and can affect creatures otherwise immune to extra damage from critical hits or more than 30 feet away, provided they are living, non-mindless creatures not immune to mind-affecting effects.)
A mind blade deals this extra damage only once when this ability is called upon, but a soulknife can imbue his mind blade with magical energy again by taking another move action.
Once a soulknife has prepared his blade for a eldritch strike, it holds the extra energy until it is used.
Even if the soulknife drops the mind blade (or it otherwise dissipates, such as when it is thrown and misses), it is still imbued with magical energy when the soulknife next materializes it.
At every four levels beyond 3rd (7th, 11th, 15th, and 19th), the extra damage from a soulknife’s magical strike increases as shown on the Table above.
Free Draw (Su)
At 5th level, a soulknife becomes able to materialize his mind blade as a free action instead of a move action.
He can make only one attempt to materialize the mind blade per round, however.
Shape Mind Blade (Su)
At 5th level, a soulknife gains the ability to change the form of his mind blade.
As a full-round action, he can change his mind blade to replicate a longsword (damage 1d8 for a Medium weapon wielded as a one-handed weapon) or a bastard sword (damage 1d10 for a Medium weapon, but he must wield it as a two-handed weapon unless he knows the Exotic Weapon Proficiency (bastard sword) feat).
If a soulknife shapes his mind blade into the form of a bastard sword and wields it two-handed, he adds 1½ times his Strength bonus to his damage rolls, just like when using any other two-handed weapon.
Alternatively, a soulknife can split his mind blade into two identical short swords, suitable for fighting with a weapon in each hand. (The normal penalties for fighting with two weapons apply.) However, both mind blades have an enhancement bonus 1 lower than the soulknife would otherwise create with a single mind blade.
Mind Blade Enhancement (Su)
At 6th level, a soulknife gains the ability to enhance his mind blade.
He can add any one of the weapon special abilities on the Table: Melee Weapon Special Abilities that has an enhancement bonus value of +1.
At every four levels beyond 6th (10th, 14th, and 18th), the value of the enhancement a soulknife can add to his weapon improves to +2, +3, and +4, respectively.
A soulknife can choose any combination of weapon special abilities that does not exceed the total allowed by the soulknife’s level.
The weapon ability or abilities remain the same every time the soulknife materializes his mind blade (unless he decides to reassign its abilities; see below).
The ability or abilities apply to any form the mind blade takes, including the use of the shape mind blade or bladewind class abilities.
A soulknife can reassign the ability or abilities he has added to his mind blade.
To do so, he must first spend 8 hours in concentration.
After that period, the mind blade materializes with the new ability or abilities selected by the soulknife.
Blade Speed (EX)
The soulknife gains a bonus of +10 feet to his base land speed at 6th level. This benefit applies only when he is wearing no armorm or light armor, and not carrying a heavy load.
At 9th level, a soulknife gains the ability to momentarily fragment his mind blade into numerous identical blades, each of which strikes at a nearby opponent.
As a full attack, when wielding his mind blade, a soulknife can give up his regular attacks and instead fragment his mind blade to make one melee attack at his full base attack bonus against each opponent within reach.
Each fragment functions identically to the soulknife’s regular mind blade.
When using bladewind, a soulknife forfeits any bonus or extra attacks granted by other feats or abilities (such as the Cleave feat or the haste spell).
The mind blade immediately reverts to its previous form after the bladewind attack.
Greater Weapon Focus (Mind Blade)
A soulknife gains Greater Weapon Focus (mind blade) as a bonus feat at 9th level.
Knife to the Soul (Su)
Beginning at 13th level, when a soulknife executes a eldritch strike, he can choose to substitute Intelligence, Wisdom, or Charisma damage (his choice) for extra dice of damage.
For each die of extra damage he gives up, he deals 1 point of damage to the ability score he chooses.
A soulknife can combine extra dice of damage and ability damage in any combination.
The soulknife decides which ability score his eldritch strike damages and the division of ability damage and extra dice of damage when he imbues his mind blade with the eldritch strike energy.
Multiple Throw (Ex)
At 17th level and higher, a soulknife can throw a number of mind blades per round equal to the number of melee attacks he could make.
Level B.A.B Fort Ref Will Special
1st +0 +0 +2 +2 Mind blade, Weapon Focus (mind blade),
2nd +1 +0 +3 +3 Throw mind blade
3rd +2 +1 +3 +3 Eldritch strike +1d8
4th +3 +1 +4 +4 +1 mind blade
5th +3 +1 +4 +4 Free draw, shape mind blade
6th +4 +2 +5 +5 Mind blade enhancement +1, Blade Speed
7th +5 +2 +5 +5 Eldritch strike +2d8
8th +6/+1 +2 +6 +6 +2 mind blade
9th +6/+1 +3 +6 +6 Bladewind, Greater Weapon Focus (mind blade)
10th +7/+2 +3 +7 +7 Mind blade enhancement +2
11th +8/+3 +3 +7 +7 Eldritch strike +3d8
12th +9/+4 +4 +8 +8 +3 mind blade
13th +9/+4 +4 +8 +8 Knife to the soul
14th +10/+5 +4 +9 +9 Mind blade enhancement +3
15th +11/+6/+1 +5 +9 +9 Eldritch strike +4d8
16th +12/+7/+2 +5 +10 +10 +4 mind blade
17th +12/+7/+2 +5 +10 +10 Multiple throw
18th +13/+8/+3 +6 +11 +11 Mind blade enhancement +4
19th +14/+9/+4 +6 +11 +11 Eldritch strike +5d8
20th +15/+10/+5 +6 +12 +12 +5 mind blade