[Primed Shred] can be swapped for [Vile Acceleration] or another mod of your choice. I just like [Shred] to shoot through lures and the yellow balls that Garry shoots.

If your riven doesn't have CC just use [Critical Delay] to get 100% + CC for guaranteed damage. Try to get 3.0 Multishot, if not then go for 2.0 and more base damage.

Try it out and change what you want.

DPS Volt Build
Pandero Prime Build
Vastilok - [Sarpa] and [Redeemer] are similar
Itzal
Wyrm Prime
Wyrm Gun - lol