Just slash, I have tested a viral build but wasn't getting satisfying results with [Virulent Scourge] and [Vicious Frost] or [Fever Strike] and [North Wind], I decided to try the gladiator mods. I prefer them because the slashes takes chunks off so quick and it can hit orange, sometimes red crits by itself without using companions with gladiator mods or warframe abilities, as the builds with viral, at least for me, hit yellow crits, orange max, and its personally more satisfying with darker crit colors.