~~~Race
Shalore: Timeless and Magic of the Eternals are excellent for a Shadowblade. There's really no other option for a race if you want to do your best. Racials are explaiend below in the Generic Trees section.

~~~Brotherhood of Alchemists and other Bonuses
-Elixer of Foundations: +2 Genetic Points
-Elixer of Focus: +2 Class Talent Points
These are essential. Any other elixirs are gravy.
-Wyrm Bile: After you have 5 inscriptions (see below), use this to bring Spell / Temporal from x1.00 to x1.20. Time Shield and Essence of Speed are the core abilities of this build.
~~~Stats

DEX > CUN > CON
Max these three.
Early on you'll want to put roughly 20 points base in MAG and then use items to help you allocate your skill points in the Spell / Temporal and Spell / Conveyance trees.
Use STR as your dump stat at the end of the game. You shouldn't need it earlier for the best Shadowblade items.
~~~Class Trees
Technique / Dual techniques

-Dual Strike: Only needs 3 points to get the stun duration the same as the cooldown.
-Flurry: 5 point nuke. Great for proc effects.
-Heartseeker: Unnecessary. Shadowstep covers this much more effectively.
-Whirlwind: Not important enough to build to. AoE covered by Whirlwind prodigy.
Technique / Duelist

-Dual Weapon Mastery: Damage penalty reduction for your daggers. Gives you parry. Don't neglect defensive skills.
-Tempo: Stamina regenerating skill. I put 1 point early but didn't stress filling it out until the end game.
-Feint: Defensive skill. Don't neglect them! Rogue classes are too squishy.
-Lunge: It might be nice to have a disarm for some bosses but I just couldn't justify the points.
Cunning / Stealth

-Stealth: Stealth is great for positioning, crits, dropping aggro. Max it in the mid to late game.
-Shadowstrike: Opens up every fight with a crit. Helps you clear out trash and get a good first hit on bosses. Max early.
-Soothing Darkness: Not important. 1 point and move on.
-Shadow Dance: Only needs 4 points for max duration. The last point is only helpful for trying to escape an engagement and you have better abilities for that.
Cunning / Lethality

-Lethality: Crit chance and bonus damage. Max it out in the late game.
-Expose Weakness: One point for those beefy bosses. Doesn't need more than that.
-Blade Furry: Attack speed is nice but AoE is covered by your first prodigy. Points are better elsewhere.
-Snap: Not worth building to it.
Cunning / Shadow Magic

-Shadow Combat: 1 point. It's just going to drain your limited mana. Don't worry about using it early. It synergizes with your second prodigy (Armour of Shadows) in the late game.
-Shadow Cunning: Max it late game. Benefits your Time Shield.
-Shadow Feed: A sustain that gives you mana regen and attack speed. Max it in the mid to late game.
-Shadowstep: Excellent opener. Put points in it as early as possible. Synergizes with the Armour of Shadows prodigy. One-shots a lot of bosses when you finish putting points in it. If you feel comfortable pulling a point out of something else, go ahead and make it 5/5 for a little extra damage.
Spell / Temporal

-Congeal Time: You'll never use this. 1 point and move on.
-Time Shield: Rush this. Max it as soon as possible. Open up every fight with it. This is one of the defining abilities of this class.
-Time Prison: You'll never use this. 1 point and move on.
-Essence of Speed: The other defining ability of this class. Max it out in the mid-game.
~~~Generic Trees
Race / Shalore

-Grace of the Eternals: Great to have. Doesn't need more than 1 point. Open up every engagement with it.
-Magic of the Eternals: Crit chance and Crit power bonus. Not important to max out early but you will before the end of the game.
-Secrets of the Eternals: Invisbility lowers the damage you deal. Keep this sustained or not depending on your taste.
-Timeless: Max as soon as possible. Lowers debuff durations, raises buff duration and decreases cooldown of your talents.
Technique / Combat Training

This tree is pretty straightforward. Max out Daggers, Light Armor, and Thick Skin. If you absolutely need generic points elsewhere, pull a couple out of accuracy... but I'd pull those points out of the Conveyance Tree first.
Technique / Mobility

-Disengage: You have better escapes. 1 point and move on.
-Evasion: It's nice ability to have but you'll probably get it from items.
-Tumble: You have better escapes and positioning abilities.
-Trained Reactions: This is going to save you from bullcrits against you and other dumb situations. It's a stamina drain in the late game but I believe it's still worth it.
Cunning / Survival

If you can, get Heightened Senses and Track from thief escorts. If you're unlucky and don't get them, you'll want Heightened Senses for sure so you can see enemies outside your 1 sight radius while stealthed.
Spell / Conveyance

Both are escapes. You're a rogue, getting out of bad situations is what you do. 1 point will do in each, but if you want absolute certainty in where you end up, 5 points can mean the difference in a successful escape and running into another bad situation.
~~~Prodigies

Prodigies should be used to cover your weaknesses.
-Windblade: You have virtually no AoE. This is absolutely essential at lvl 30. It's a good idea to get it before Dreadfell.
-Armour of Shadows: Synergizes with Shadowstep and Shadow Combat. If you get an weapon that adds a little shadow damage you'll have the bonus evasion and armor at all times.
~~~Category Points & Inscriptions
Put your first Category Point into Spell / Temporal and then put the the next two into Inscriptions to get the max of 5. Use your last Category Point (probably from Wyrm Bile) to bring your Spell / Temporal from x1.00 to x1.20.

-Rune: Shielding: Synergizes with Time Shield. When the shield of Time Shield goes down, pop the Shielding Rune while health regenerates.
-Infusion: Healing: Rogues shouldn't be in a fight long enough to use Regeneration. Use it anytime Time Shield isn't about to heal you during a fight.
-Infusion: Wild:
-Infusion: Movement: Excellent for both positioning and escaping.
-Infusion: Heroism: Huge health boost. Open up every fight with it.
~~~Escorts
-Track/Heightened Senses: Frees up generic points.
-Arcane Eye: Alternative to Track. Doesn't use a turn to cast. Less coverage but longer range at rank 1.
~~~Equipment
-Watch out for Arcane Disruption items.
-Shadowstep counts as a teleport. Items that have teleport prox effects are beneficial.
-Bloodcaller: Obtained from the Ring of Blood. Don't kill the end boss until after you acquire it. Must pay 150g to participate. Put the ring on and never take it off again.