Need Suggestion for Trickster Poison Build

I recently just finished the entire story until Act 10. Since I recently got Dendrobate, I decided that perhaps a spell-procced poison stack build would be nice. Thing is, I've been juggling between Ethereal Knives, Bladefall, and Unearth. Any suggestions as to what spell should I invest on this build? Perhaps there's a spell better than those 3 for Poison proccing? Thanks in advance