Evo II: Punch-Through
Evo III: Reload
Evo IV: Crit

Replace Riven with (Amalgam) Serration or Hunter Munitions if you don't have one.

You could also run Hammer Shot if desired, and/or drop Viral entirely -- especially with Nourish! [Bladed Rounds] can be swapped for [Hammer Shot], [Rime Rounds] for [Primed Cryo Rounds].
You can still run (Primed) [Shred] and Merciless or Primary Crux with similar efficacy. This gun is simply broken. If possible, outsource Viral to Nourish or run Roar with Viral + Heat. Currently enjoying a [Thermal Transfer] Blast build on any Warframe comfortable with Thermal Sunder.
Also, [Stabilizer] is a perfectly fine Exilus for QoL! I have been using it more often since the DPS on this gun is just insane.

With the Headshot Multiplier stacking with [Galvanized Scope] + Primary Deadhead. This does even more damage than shown. This does upwards of 250 Million DPS on headshots, with all multipliers accounted for. If you add in Roar or Xata's, you're looking at 500-750 Million headshot DPS.