A FL4K build themed around corrosive damage with an emphasis on corrosive-only gear. Obviously not an optimized build (because it's only corrosive, duh) but it can easily handle most content at M10/11 (yes, even enemies without armor) with proper FL4K strats.
As a general rule for anointments, ASE splash is best followed by N2M. Consecutive hits, 300/90 and ASE 100 can work as well.
Note: All gear and anointments should be corrosive (if possible) both for the sake of the theme and for maximum Flesh Melter synergy.
- Reflux - A favorite of Fade Away FL4Ks everywhere and the main weapon of this build. This is your best mobbing tool due to its amazing crowd control potential and synergy with Head Count. Normally not so great with lone enemies but there are ways to get around that.
- Gargoyle - Best for lone enemies. It's very ammo-hungry though so be careful about using it for extended periods of time.
- Breath of the Dying - Great for mobbing provided you can stay out of the way of the orbs. Two things to keep in mind when gearing for this gun: 1. the bullets are not boosted by assault rifle damage, 300/90, Hidden Machine, the Hunter's Eye armor bonus or the DE4DEYE's special effect. 2. Using a grenade/shield elemental anoint can sometimes prevent the orbs from spawning on kill.
- Hornet - Not as strong as the Gargoyle but still very good and generally easier to get.
- Plaguebearer - Best overall heavy weapon for FL4K due to the multitude of homing projectiles as well as the fact that you can't down your pet with it. The charge is annoying but short enough so that you can get three Fade Away shots in fairly easily (provided you have Persistence Hunter).
- Sand Hawk - This is probably the best corrosive sniper for a Fade Away build right now (the Complex Root does more damage but the burst fire restriction ruins it for Fade Away). I normally use semi-auto because it has pretty good one-shot potential with Fade Away and an amp shield but really any firing mode will work well.
Unfortunately sliding/shield regen is currently not in the anoint pool so try ASE corrosion, cooldown or terror (provided you have a Ghast Call) for your shield anoint instead.
- Impaler - It deals corrosive damage, it's easy to acquire and it always has a solid recharge due to its (locked) parts making this shield a great match for Fade Away. It can even kill enemies sometimes too.
- Gas Mask - If you're looking for a meatier alternative to the Impaler. The main draw of this shield for FL4K is its ability to roll with three extra parts; its main ability is kinda whatever unless you decide not to take Lick the Wounds for some reason.
- Bounty Hunter, Cosmic Stalker, DE4DEYE, St4ckbot - All of these will work for this build. I generally roll with Bounty Hunter due to its versatility as well as its synergy with Interplanetary Stalker, the only point-based skill in the game with a corrosion-specific attribute.
Go with ASE corrosive or OGT depending on what anoint you have on your shield.
- Ghast Call - Does a shit ton of damage and it comes in only corrosion too. Vindicator is the best version but really any roll will work well. The child skulls all home which is great for Pearl stacking and Buddy System destroying. Note that the Ghast Call cannot spawn with an anointment.
- Hunter-Seeker - If you don't have a Ghast Call go with this instead.
- Flesh Melter - Not the greatest for bossing but for mobbing with corrosive weapons it's absolutely one of the best choices out there especially if you're using a corrosive weapon with crowd control potential. The exact artifact is up to you; I like Otto Idol for the survivability but that's just me.
- Pearl of Ineffable Knowledge - Use this for bosses. Your grenades are your best tools for getting stacks quickly.
Obviously there's the skill tree below but I'm including this section just to justify certain skill choices I've made.
- Fade Away - So that you can stick to doing only corrosive damage as much as possible.
- Spiderant Countess - Generally not a killer for this build but all her attacks are corrosive so in the event that she does land a killing blow you'll get a Flesh Melter stack. Her attack command is extremely useful even for non-pet builds and can be used to move her around, draw aggro and even strip weaker enemies' shields.
- Dominance build ("Full Master") - Less damage but more survivability (also with Dominance you can get Reflux chains off yourself and your pet which is great for single targets). You can find the skill point allocation here.
- Trapper build - For screwing around with pet shields. The point allocation is the same except you go halfway down Trapper instead of Master. For skills I suggest Agility Training, Combat Veterinarian, Throatripper and Take This!, with the final point being up to you.
These are the ones which I generally feel are the most important for this build.
- Corrosive Damage - This build only uses corrosive weapons so this is a no-brainer. Plus you won't always have Flesh Melter stacks so it's nice to have this as something of a safety net.
- Magazine Size - This is one of the best stat rolls in the game period and will greatly help any non-COV gun.
- [Weapon Type] Damage - This is multiplicative with gun and critical damage as well as most of FL4K's general damage bonuses such as The Power Inside. It won't do anything for Breath of the Dying but for everything else it's very good.
- Splash Damage Radius - This has amazing synergy with Hollow Point which with Fade Away and Megavore you'll proc quite often. Also helpful for taking out Buddy Systems with your pet.
- Splash Damage - This is multiplicative with all of FL4K's damage bonuses and applies to almost every weapon in this build but when combined with the already very powerful splash anoint it doesn't do much; however if you don't have access to the splash anoint then this is really good.
Any modifier combination of your choice is fine but avoid Acid Reign and Dazed and Infused at all costs. This build uses almost exclusively corrosive damage so corrosion-immune enemies are naturally the worst thing for it.
Use Fade Away as much as possible; this is especially good for having amp damage ready. When not in Fade Away, use the Reflux to proc Head Count (and also kill enemies). Against singular enemies (especially beefier ones) other weapons such as the Gargoyle are better choices; if attacking and Fade aren't viable options then run away and let Topped Off bring Fade back for you.
It's often a good idea to have your pet close to an enemy before you end Fade Away so that they will activate Not My Circus sooner. You can also use your pet to bring far away enemies closer to each other; to do this, target an attack command on the enemy that your pet currently isn't attacking. This will bring your pet's previous target closer to the current one, allowing you to Reflux chain them.