Viral Primer/grouper. Group them together with alt-fire. Use primary fire with high multishot and punch through to stack max stacks of viral easy, swap back to primary, or use damage abilities, or if [Oraxia] watch scutllers do their thing.

I don't think anything else needs explaining. Just every status chance mod that doesn't dilute viral and encumber for bonus priming. Multishot because more multishot = more enemies grouped and more viral stacks. Awesome weapon all around.