You basicly build a trapsin, then have chaos and ideally a fools on top.
They are usually 102fcr, but d2r may use 65fcr.
There is a billion ways to build it, it one of those characters where spending loooooaaaaads in benefitial.
So where you focus actually depends on how good your gear is.
Usually claw mastery > venom.
Both trap and shadow sks are both viable. Depends on rest of items.
First decide if your going 102fcr or 65fcr.
A 65 fcr is more flexible, but ofc also way slower.
Griffon
Arach
trangs
Thats a easy way of getting 65fcr, you can add HL and Gores as damage dealers. You can use forexample raven + wisp.
That leaves a free soc in helm on top, and hl boost ias. So you then have high flexibility in claws.