New classes for a new campaige setting

PaigeXenon

I'm a relatively new DM and I'm about to under take the large project of creating a whole campaign setting. I have run a few adventures for my old group but they were all in the eberron setting now that i have moved and will be starting a new group I want a setting that is my own. I have started work on on a new class that is a modification of the soulknife class without psionics and a shadow magic feel, I just need some help balancing it and coming up with a few unique class features.
I don't have a lot done for the class yet but here is what I've got.

Abilities:
Alignment:
Hit Dice: d8
Level BAB Fort save Ref Save Will save Special

1st +0 +2 +2 +0 Shadow Blade, Weapon Focus(Shadow Blade)
2nd +1 +3 3+ +0 Two weapon Fighting
3rd +2 +3 +3 +1 Shadow Blade(Lethal), Shadow Striking +1d4
4th +3 +4 +4 +1 +1 Shadow Blade
5th +3 +4 +4 +1 Free Draw, Twin blades
6th +4 +5 +5 +2 Shadow Striking +2d4
7th +5 +5 +5 +2
8th +6/+1 +6 +6 +2 +2 Shadow Blade
9th +6/+1 +6 +6 +3 Shadow Striking +3d4
10th +7/+2 +7 +7 +3
11th +8/+3 +7 +7 +3
12th +9/+4 +8 +8 +4 +3 Shadow Blade, Shadow Striking +4d4
13ht +9/+4 +8 +8 +4
14th +10/+5 +9 +9 +4
15th +11/+6 +9 +9 +5 Shadow Striking +5d4
16th +12/+7 +10 +10 +5 +4 Shadow Blade
17th +12/+7 +10 +10 +5
18th +13/+8 +11 +11 +6 Shadow Striking +6d4
19th +14/+9 +11 +11 +6
20th +15/+10/+5 +12 +12 +6 +5 Shadow Blade


Weapon and Armor Proficiency: Shadow Knives are Proficient with all simple weapons, with their own Shadow Blades, and wiht light armor and shields (except tower shields).

Shadow Blade (su): This abillity is like the Mind Blabe except it only does non lethal damage until 3rd lvl and can only make daggers. At 3rd level teh damage becomes lethal and the shadow knife is able to form the blade in to a short sword or kukri.

Two weapon fighting

Shadow striking: At 3rd The shadow blade gains an ability that allows it to do an addition 1d4 damage while being wielded with in an area of shadowy illumination or darkness. Both the wielder and their target must be in the area for this effect to work. This extra damage does not effect creatures that are immune to critical hits.
The damage done increases by 1d4 every 3 levels. A shadow knife can sacrifice 1 extra damage die to change the type of damage by the other dice to cold damage.

Free Draw: A shadow knife can create its shadow blade as a free action.

Twin blades: The shadow knife has the ability to create a second blade at -1 than the first





That all I have so far Any suggestions would be great, Shadow magic will be a big part of my campaign so any ideas features, other classes or races that will help my setting keep the shadowy feel would also be nice.

Thank you all in advance for all your help. XD