1: Introduction
A semi auto, single target long rifle with low fire rate and no innate punchthrough. [Prisma Grinlok] was released way back in 2019 and it doesn't age that well in the current "horde shooter" meta where enemy density is too high for pure single target guns and everyone use them chaotic explosives/chain beam/full auto to wipe out the mobs. Still, if you somehow fell in love with this gun and want to use it for higher contents, this build provides the best results for the fewest investment possible (in my personal opinion, that is). Tested up to Steel Path Kuva Fortress, will or will not work at endurance level.

2: Requirements

• A blue potato (a.k.a Orokin Catalyst)
• 2 Forma

3: Mods:
Galvanized Aptitude/Chamber: You will wanna slap these babies into any guns you get from now on. Bought from Arbiters of Hexis using Vitus Essence.
[Deadly Sequence]: 200% Critical Chance for 7 Mod Capacity ? YES, please. Not every gun has this kind of treat. ([Kuva Hek] cried in a corner) The Sequence effect will even provide some crowd control Radiation procs, but it will alert enemies and mess up your stealth game. Got from Perrin Sequence syndicate, or you can get players that allied with the faction to smuggle out one for you.
[Critical Delay]: Combined with [Deadly Sequence] to give your gun 105% Critical Chance. Go get some Dragon Keys and grind Deimos Orokin Vaults (not Cambion Drift) till you get one.
[Hunter Munitions]: Gives you more Slash procs, which ignores the absurdly high armor enemies have in Steel Path.
[Vital Sense], [Hammer Shot], Primary [Frostbite]: Add critical damage to the gun. You have 105% Critical Chance to work with, no? Get Vital Sense from normal gameplay, Hammer Shot from Nightmare missions and Primary Frostbite from Conjunction Survival on Lua/bought from Archimedian Yonta in Chrysalith using Lua Thrax Plasm.
[Rime Rounds]: Combined with [Hammer Shot] and Galv Aptitude for 100%+ Status Chance, with Cold damage for triggering Primary [Frostbite].
If you don't have access to those mods, either farm them or buy from other players with plat.

4: FAQ
Q: Why no raw damage mods (Amalgam/[Serration], [Heavy Caliber])?
A: [Galvanized Aptitude] (a.k.a Gundition Overload) gives you +80% raw damage per status type affecting the target. With 118.4% Status Chance, area Radiation proc, somewhat even Cold/Slash/Impact damage distribution, Hunter Munitions and more multishot from Frostbite, the gun itself can consistently pump out 3-4 Status types for Galv Aptitude to work with. Besides, most enemies will die from Slash procs, not upfront damage.

Q: Why Primary Frostbite?
A: It's one of many choices, you can replace Hammer Shot with Malignant Force for Viral and use Merciless/Deadhead/Dexterity. After testings, I choose [Frostbite] because:

• You can get Viral status from external sources, for example [Panzer Vulpaphyla] or subsumed Nourish
• A rank 7 [Malignant Force] and [Rime Rounds] will shift the Slash weight of the gun, making you reliant on [Hunter Munitions] for consistent Slash procs. Slash proc damage will however scales with the gun's total damage, which means you're trading less procs for more proc damage.
• Cold element, with its slow effect, will decrease enemies' animation speed, which means their head will move around less and allow you to score headshots easier. And since [Prisma Grinlok] have low fire rate, you will want to make the best out of every shots.
• More critical damage on a gun that can achieve 100%+ critical chance without Riven. And more multishot, which gives you more Slash procs.
  +Deadhead only triggers with DIRECT headshot kills, so a damage over time reliant build like this can hardly utilize it. Merciless has a mere 4 seconds duration which makes ramping up the stacks in the beginning somewhat inconvenient, especially when you'll often need more than 4s to kill with this gun. [Frostbite], however, ramps up ON HIT so you only need to shoot.

Rule of thumb: on Grineer use Cold + [Frostbite], on Corpus use Toxin + Merciless but keeps [Hunter Munitions], there're some Corpus enemies with armor too.

Q: Which slot is flex slot and which Riven stat is good on this gun?
A: The usual: Critical Chance and Critical Damage. Fire rate is an immense help, too. Galv Chamber and [Frostbite] gives you a lot of multishot already, but more won't hurt. For factional damage, aim for Grineer or Corpus. Steer clear of raw damage, it's not worth it. For negative, -Puncture or -Damage against Infested will do, -Impact will work but then you'll likely lose 1 element for Galv Aptitude. Since Prisma Grinlok have high dispo -Fire Rate is very noticeable (will turn Grinlok into Vulklok, if you know what I mean) so don't get it unless you're willing to use the gun with Wisp/Gauss/Arcane Accelerate.
For flex slot, if your Riven have critical damage, slot it in instead of [Vital Sense]. If status chance, [Hammer Shot]. If it have Cold damage, [Rime Rounds]. If your riven have both Cold and Toxin then congratulations, you have Viral packed in 1 slot, switch it out with [Rime Rounds] and use Merciless instead of [Frostbite].
All in all, after slotting Riven you'll need to keep your Critical Chance and Status Chance above a MINIMUM of 80%. [Prisma Grinlok] already have slow fire rate so anything lower will proc less consistently (not counting multishot, that is).
Do note that in order to fit a Riven into this build, you need to put 1 more Forma into this gun.

Q: Is factional damage viable?
A: Yes, but only when you have Primed Bane, normal Bane is often not worth the slot. Put it instead of [Vital Sense] or [Hammer Shot], but you'll need to put 1 more Forma into this build for that.