Note to self: get CC and CD/Dmg (dmg type optional) on the Riven. Getting over 100% CC on primary fire would be awesome.

Naramon polarity in row 2 mod 3 ([Pathogen Rounds], [Convulsion], [Primed Heated Charge]) leaves enough mod capacity when not using an Exilus mod to instead fit a status+dmg mod, regardless of it being the wrong polarity. If you are using a matching polarity mod in that slot, you can use a 7 or lower cost Exilus mod as long as it's a matching polarity.
This also makes it easier to switch [Primed Heated Charge] around to change damage types, instead of requiring you to shift polarities around for each faction.

Eight forma just feels like way too much, but it's practically required if you plan on using all mod slots and a Riven. To anybody reading this, try your best to get a [Sepulcrum] Riven that's Naramon polarity (dash). Not Madurai (V). Much easier to shift damage types around that way if you're sticking with an elemental damage roll.