Exalted Umbra Blade - Suitable up to Steel Path level 190 and beyond.
100% Status build through Chromatic Blade. Guaranteeed Red Criticals - 18.3x damage. Prerequisite Excalibur Umbra Build: https://overframe.gg/build/69649/
Primed Fever Strike, Shocking Touch and North Wind for Corrosive and Cold to combat all armor types; Corrosive to melt with bonus damage to ferrite armor, Cold For Critical Multiplier, synergy with Archon Flow.
Viral is an option, but doesn't make much sense. Weaker enemies can be killed with one-hit, only stronger enemies with extremely high armour require two or more. In cases of extremely high armour, Corrosive is better than Viral.
Condition Overload to increase damage massively with each consecutive hit.
Organ Shatter to make use of Sacrificial Steel, overall small but noticeable increase in DPS over regular [Exalted Blade] for regular attacks.
Combined with the Helminth Wrathful Advance, causes a significant increase to damage since Wrathful Advance combined in my [Excalibur Umbra] build guarantees Red Crits with 18.3x damage.
Melee Duplicate further effectively doubles your damage output. Melee Duplicate gives you a bonus hit when a Crit is achieved, this means you get a bonus hit automatically when using Wrathful Advance. Further, Wrathful Advance also effects this bonus hit allowing it to be a Red Crit. Unlike weapons that rely on combos, this gives you a truly effective doubling of damage.
If you want extra survivability at Steel Path, replace North Wind with Healing Return, though not necessary thanks to Adaptation
Feel free to use Dreamer's Wrath or Discipline's Merit as the exilus mod. Allowing you to stack heavy attacks with your attacks with high efficiency.
Video demonstration: