• Archon Shards :

1. Emerald (+2/3 Corrosive)
2. Emerald (+2/3 Corrosive)
   ... Flex

Loadout Ideas :

Every [Nidus] build with Teeming Virulence should be focused around primaries for either massive crowd-killing or insane dps.
Hence secondaries or melees will depend on chosen primary : killing acolyte, priming, crowd-killing, buffing, etc...
Infested-like weapons are recommended for maximum drip !

• Primaries :
  Mutalist Cernos great tool for single-target dps or groups when larva is up. Always use uncharged-shot.
  Kuva Bramma becomes a monster with the huge crit buff. Insane Acolyte killer and very good at crowd-killing at base SP.

• Secondaries :
  Sporelacer is a very good acolyte and fodder killer that doesn't require any buff. Will be used in tandem with Pathocyst for viral priming, arcane staking and CC+SC buffs.
  Epitath epitath is just epitath. Larva makes it even more useful.
  Kuva Nukor IF Arcane Avenger is equipped, nukor is a solid option.

• Melees :
  Pathocyst use to spread viral and usually buff our seconday, build can be swapped for a heavy attack spam.

• Companions :
  Djinn An absolute must for high lv content since [Nidus] lacks gating mechanics (aside of his passive). Provides great utility too !
  Helminth Charger 2nd infested themed companion, this time the build needs to be adapted on nidus and pathocyst to fully utilize strain mods set.