Legendary Radiance for blinding procs

VS

Legendary Vaccuum for quick stacks of Vulnerability

I haven't messed around much with the active augment slots, they all look pretty trashy to me, unless im missing something. I would go with the t3 augment bonus of legendary radiance, put that in the crafting planner first, then spec the lower tiers according to whatever suits your gear and play style.

The radiance will blind your foes, increasing sneak dmg and helping them miss you and your party. I would choose this over the vacuum, unless you are a solo player, because chances are a caster nearby will already be making things vulnerable for you.

Some LGS can have insightful 7 con on them, which helps for gear tetris.
The stacking healing amp is also useful. If you're TWF you can use one of these in a difficult encounter.

Effects every melee should include in their golf bag:
Mineral: put healing amp or stacking devotion on tier 1, tier 2 put insightful con, tier 3 good damage
Salt: slows enemy down tremendously. Internal cooldown sucks.
Ooze: tier 2 can be insightful 7 con. These oozes are hilarious. The ooze affect also strips the bosses in LE shroud and any other mobs you encounter with PRR or MRR; however this does not affect DR/- which the Erinyhes has.
Vaccuum: mainhand most of the time.

Rad: I wouldn't reccomend this because blind mobs are annoying as fuck, but it depends on the difficulty of the content.

Assassin's Kiss.