Harlow - Shockingly Radioactive - ENDGAME

Guns:
Mobbing: Complex Root paired with Firewerks makes short work of the majority of trash mobs. You can also use Katagawa's Revenge but I'm using the legendary Malawan Enhancement called Merciless Lame.

This pairs Synthesizer and Mixologist together so having Shock and Radiation on Complex Root further increases the radiation damage done.

Lucian's Flank and Rainbow Vomit are also fun guns to use but not as powerful as the others.

Bossing: Plasma Coil with shock and radiation, for the same reasons as above, absolutely shreds bosses once you have Neutron Capture rolling. Complex Root also works extremely well but a fast firing Luty Madlad is also extremely powerful but I haven't found a decent one myself.

Repkit:
Shiny War Paint I've found works extremely well, but make sure it has the Accelerator perk on it for more cooldown reduction.

Class Mod:
The Scientist class mod makes it so any time you shock an enemy you also apply radiation AND entangle the enemy, this can stack up status effect damage extremely fast on bosses and mobs alike.

Try to get Ripple Effect and Action at a Distance +5 on it. These will spread Entanglement and status effects to mobs in the area very fast and it works well on bosses that spawn adds constantly as well.

For passives mine has +25% Action Skill Cooldown Rate and +35% Splash Damage.

Shield:
There are quite a few options for shields but personally I stick to a good rolled Firewerks with lightning resist as that allows the missiles to also apply radiation.

I have Heavy Plate on mine just for some comfy damage reduction.

If you would rather a shield that focuses on pure damage reduction than something like Pandoran Momento is very powerful.

Enhancement:
So I am currently using a legendary Malawan Enhancement called Merciless Lame. This has Synthesizer which adds +25% status effect damage, and Mixologist which adds 10% to the damage type of the inactive mode's element.

When using the guns above paired with the class mod you want to be using the Shock modes as this synergises well with everything to be constantly buffing radiation damage while also dealing a lot of shock damage at the same time.

Stats wise try to get Mag Size, Sniper/SMG Mag Size, Fire Rate, SMG Fire Rate, Splash damage or Gun damage. Any of those together will work well.

If you use Luty Madlad then you want a Daedalus enhancement with the 50% fire rate stacking buff.

Ordnance:
You probably already know what I'm going to say but yes, unfortunately, a Jakobs throwing knife with Penetrator Augment + Damage Amp Payload is by far the best choice for this slot. The sheer damage both of those debuffs add is immense and I feel like might get nerfed at some point.

If you can't find a knife with both, aim for Penetrator Augment first.

Firmware: Aim for 3pc of Deadeye paired with 2pc of Bullets to Spare.

ITEM DROP LOCATIONS:

Guns:
Complex Root - Mimicron / Order Bunker / Tipping Point
Katagawa's Revenge - Driller Hole / Tonnage Peel / Queen's Cradle
Plasma Coil - Timekeeper / Terminus District / Upper Dominion
Luty Madlad - Mimicron / Order Bunker / Tipping Point
Rainbow Vomit - Leader Willem / Grindstone of the Worthy / The Excrucible
Lucian's Flank - Saddleback / Ripper Drill Site / The Old Scrape

Class Mod:
Scientist - Primordial Guardian Radix / Vault of Radix / Grindstone of the Worthy

Shields:
Firewerks - Splashzone / Coastal Bonescape / Fadefields
Pandoran Momento - World Drop (sadly)

Repkit:
War Paint - Saddleback & Immortal Boneface / Ripper Drill Site / Cuspid Climb

Enhancement:
I'm fairly certain all enhancements are just world drops but a few people have speculated that the end of zone bosses have a higher chance to drop them. So far I've found very few legendary ones.

Ordnance:
Same as above, since this weapon isn't a legendary, there's no real way to target farm it, just farm the boss you find the fastest (for me I got my god roll from Mimicron while getting other items).