MANDATORY MODS:
Viral Quills - spreads AOE viral procs and minor damage
Martyr Symbiosis - sacrifices itself to save you. You can then immediately revive it using Aerial bond + Tenacious Bond (jump and get kills + headshots)
Panzer Devolution - allows you to regenerate every 30s on death, rather than the 60s cooldown for normal pets.
Fetch - mandatory vacuum

OPTIONAL MODS:
Tek Assault - 60% chance to not die, OPTIONAL mod, since Panzer can simply revive in 30s
Synth deconstruct - OPTIONAL for mass producing health orbs, as any enemy touched by [Viral Quills] has a 25% chance to drop health orb. also gives holster reload bonus.
Primed Animal Instinct is OPTIONAL since you now get universal radar, but loot radar is still useful
Rank 5 minimum Bite + Tenacious Bond - gives free 1.2x flat crit damage to your weapons, OPTIONAL mods

Seismic Bond - OPTIONAL, but gives 30% bonus Ability Efficiency on warframes with "CHANNELLING ABILITIES" as [Viral Quills] deals damage. Note that the game has a VERY generous definition for channeling abilities as nearly every frame has an ability that seems to count. See Arcane Intention wiki page for a full list: https://warframe.fandom.com/wiki/Arcane_Intention

Flex options:
Hunter Recovery - optional mod for healing. [Viral Quills] constantly heals your health while active since it deals damage.

Calculated Redirection + Reinforced Bond (eg drop Primed Animal Instinct/Tek Assault) - for bonus 60% fire rate

Tandem bond - good on frames requiring melee combo eg [Baruuk], [Gara], [Khora], [Atlas]. [Viral Quills] count as an extra 3 melee combo per spore, meaning Panzer attacking gains up to 18 combo per enemy hit (assuming up to 6 spores). You can reach x12 combo in 10 seconds if you add grouping.

Mystic Bond - allows free casts on frames that don't use [Brief Respite] for shield gating, and [Viral Quills] helps trigger [Mystic Bond]