Before anything Happy Tennocon! here is a gift for everyeone so you can share to anyone!
All Warframe Weaponry Graded!

The Toxin [Kuva Zarr], Did you know Radial Attacks do Headshots as much the projectiles? it is 3 projectiles per Round in total of 15. Probabilities? Being negative toward conclusions.
For an ideal Riven you can get a CC,CD,MS to Replace [Vital Sense] for overall damage.
For Faction Damage You can replace [Serration] for the desired Faction Damage.
The damage lost from [Serration] is regained by the arcane Primary Merciless.

At then end you need to put 5 Forma on this weapon and obligatory to be Toxin since you need to put Primed Fast Hands.
This same Scheme works for SC build for [Kuva Zarr] but after several tests this weapon performs better Full CC.

Why some people prefer Faction Damage mods than Damage mods as [Serration]?
it happens to be that Faction Damage mods are Multiplicative Damage while Damage is plain damage as additive.

Lets says, Faction Damage Mods work like Multishot Mods.

Some people Alternatively they add the multishot mods instead of [Serration]. Now here's where it gets tricky because the effect of multishot is not ADDITIVE like the DAMAGE is, Multishot IS multiplicative.
But we're still forgetting something. The multishot also adds more rounds, rounds means more Status chance procs!

At the end having a Faction Damage Mod is better than having plain Damage Mods as [Serration] or [Heavy Caliber] because you would prefer to Multiply your damage as 10x10 than add more damage like 10+10.
Myself I use Faction Damage Mods but here I share what I call a Customable 'Scheme' which you can change Status and Damages as you like, it is perfect since you won't waste more forma.
As I Did.