Zenurik and Focused Energy is used to create a positive feedback loop of ramping to 12x combo, then beginning a heavy slide-attack, and ramping back to 12x. We don't worry about losing combo because we swap to guns during times melee won't be used, using the Granum Attaché.
1 Forma is used for the stance slot in order to allow more versatility in the bundle, because we won't be changing the stance - unless there's a drastic change to stances.
Toxin is targeted as the progenitor element to allow swaps between Corrosive (blended attack types), or Viral for more combo attacking.
Either blended or combo attacking setups are valued here. If combo is preferred, recommend considering swapping [Sacrificial Steel] to [Primed Reach].