Solo traps, duo traps, raven blessing+hide behind NPC trick and
trap heroway but with a REDUCED DROP/GEM due to heroes sharing.
Well, for the sake of sharing something that may help, heres a simple trick
I do with my heroes to kill all of the stygian waves and GET ALL THEIR DROPS ALL FOR MYSELF
Also can be used to farm event items due to the sheer amount of mobs
Every full run will ensure 4-10 stygian gems, golds and random normal tomes (necro, ranger, derv etc).
With practice, you can completely wipe all waves in 6-9 mins.
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SKILLS:
Your skills:
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Heroes skills:
Hero 1 (Ranger/Mesmer):
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Hero 2 (Ranger/Mesmer):
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Hero 3 (Monk/Ranger):
OwITAHLj5B5kcUOE3lDDB68rBA
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EQUIPTMENTS
Staff with +15 energy
I use Mindclouder
or anything that wil give you 45-52 raw energy
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The Farm
1) Enter Stygian gate in Hardmode press alt and target the ADEPT OF WHISPERS to activate the quest.
N.B. You may have to wait for a passing patrol you may meet going to the NPC quest giver

This will activate the waves
After getting the quest, wait at this spot till the 1st wave have settled around the NPC

and run around the center block till you reach this place

Once there, DO NOT FORGET to FLAG YOUR HEROES on A SINGLE TIGHT SPOT (over each other so as to focus the traps effectiveness) while you remain a bit at their back
Heres how it looks like:

Begin laying your traps in this order
This has to be done simultaneously = You have to micro all your heroes
1) All Spirits EW QZ EoE WINNOWING
2) Serpents Quickness for the whole party
3) Echo traps for the first and second heroes
For the third and your traps, lay them as they are sequenced at the bar.
Lay as many as you can while Energizing Wind is up.
N.B. SIRITS have a 60 Minute RECHARGE time while TRAPS have a 90 SECOND gap till they expire.
It gives you 60 seconds to lay traps using your spirit skill recharge as timers and use the remaining 30 seconds to reflag hero and AGRO.
After you layed all your traps (roughly around 25-30 traps based on how fast you can do it - takes practice) unflag your heroes and flag them inside this GATE

The idea is to flag the away at the remaining 30 seconds you have to avoid them stealing all your drops and gems when you agro.
This is the right good spot when they can be safely flagged inside, where they wont agro any mobs passing and spawning and still be far enough not to take any of your drops.

After flagging your heroes, go back to your targets, get the nearest one and cast MARK OF PAIN to agro them plus add to the damage the traps will do. Run behind your spirits
N.B.Dont forget to use run skills both on yourself and your heroes to easily reach your destinations.

Hide behind your spirits, trust me, theyd be dead even before they reach you!
Wave 1 down.

In case you die, no worries, cast UA on your Monk/ranger hero, wait for a while till the next mobs settle, recall your heroes and rez yourself.
NOTE: FOCUS TRAPPING is used for WAVE 1 and 2 basically because they got no Stygian Fiend mixed in them. REPEAT THE SAME STEPS for WAVE 1 and 2
WAVES 3-6
So what do I do to get rid of those pesky ranged mobs (mixed with WAVE 3-6) who wont step on my traps?
For the incomming next waves, the trick is to set your high hp spirits i.e. EoE and Winnowing way back and set EW and QZ up front the same spot where you trap.
Heres how you lay the spirits.

Heres a good distance where you place EoE and Winnowing from the spot where you trap--where EW is seen placed..
When when you and hero number 3 lays down EoE and winnowing, flagg him/her immediately with those up front.

Cast Energizing wind and QZ for those up front and start laying all your traps up front on a focused spot.
Again lay as many trap for 60 seconds using your spirit skill recharge as timer, unflag heroes, put them away at the same spot, agro and run past to where your EoE and Winnowing is.
By this time, your EW ans QZ will be expired thus the fiends will target you or EoE and Win, while stepping on your traps. BOOM no more fiends
This will leave the melee type mobs which you can kill using the first method mentioned.
REZ yourself+RINSE AND REPEAT till theyre all dead.
N.B. Since you got UA in one of your heroes, feel free to bait yourself so you can control where your mobs steps on.
A single wave elimination will wipe out 60DP quickly. So dont be afraid to die.
This is also a technique i use to avoid running too far to loose agro and then going back to the trap spot---saves time.