The usual base for Shatter build is 20/20/0/0/30.
20 in Domination gives your Mind Wrack 20% more dmg and 25 stacks of Vulnerability when you use F3.
20 in Dueling gives you the trait that is essential for Shatter build:Deceptive Evasion. Keep dodging to make clones to shatter. Also CD reduction for Sword skills. Sword is the weapon you will be using 9/10 of the time.
30 in Illusions you will get the power for your Mind Wrack. You know when you have more clones out, the dmg of MW goes up? With Illusionary Persona you count as a clone and MWs dmg will go up, as there will be 4x shatter, instead of just 3. Also, when you shatter, you will get Might. When you use any shatter, you will inflict Confusion --> Cry of Frusturation will cause 8 stacks of Confusion. Also MW has 10% more crit chance. Also shatter recharge 30% faster.
You should always start the fight from range with GS, make 3 clones and when you're in melee range hit F3=25 stacks of Vuln and you get 3 stacks of Might. This will boost your dmg by 28%. Next change to sword and make another 3 illusions and use Blurred Frenzy, then hit F1. You will deal ~5k dmg with BF and 4x~2,5k with MW=~15k dmg burst (+the dmg your phantasm hits).
For off-hand, I strongly suggest a Sword. The Sword CD trait affects off-hand Sword too. iSwordsman is godly. Hits hard, is almost at melee range, but still at safe zone and it evades attacks when leaping.
Hope this helps

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