Can use ANY weapon but [Fragor Prime] has innate +30 initial combo. Combined with +30 from [Corrupt Charge], this gives +60 initial combo which translates to 1.75x bonus to Shattered Lash damage.

Can replace [Auger Strike] or any elemental with a Riven. Look for the following stats:

Positives: Damage > initial combo (needs to be at least 20 on [Fragor Prime] to hit 80, or 30 on any other melee to hit 60) > elemental > puncture > slash (puncture preferred as tapping 1 for puncture is one handed and easier than holding down 1 for slash)

Negatives: Anything except the positives