I think this is the way to save this wpn(not rlly... this wpn is pretty good, but there is waaaaayy better wpns out there).
essentially what do you need is stack up to max viral and apply as fast as possible heat, this will act like slash reducing armor to half and burning flesh

the riven doens have to break the delicate balance of the mods: if you take out [Reach] you must to have [Reach] on the riven, and so on
in theory just with weeping wound should be enough status but using [Fever Strike] or [North Wind] would break the balance

that riven is a template of that i consider the best stats, if you not have one just slap [Body Count] or [Drifting Contact] (if you use [Drifting Contact] and no riven you dont need any forma)
if you get a riven this good you can change [Virulent Scourge] and [Vicious Frost] for its full dmg counterpart

stat for a riven:

+heat, +combo duration, +initial combo, +range, +combo efficiency

-any physical, -crit dmg, -crit chance

this wpn is for those who dont want to set the world on fire, those that just want to start a flame in their hearts