Hello welcome to my guide on how to slay waterfiends. I hope it helps!
Lets start......Firstly you need some basic requirements. If you don't have some of these it will be hard (if not impossible) to kill waterfiends at a decent rate.
Reqs:-70 attack
-70 strength
-70 ranged (unless you have full void melee)
-Have completed barbarian training far enough to enter the ancient cavern.
Recommended:-68 summoning for a bunyip
-60 magic for a god cape
Here is a recommended setup.Items used: () indicate substitutionsHead-full slayer helm (slayer helm/helm of netiznot)
Neck-amulet of fury (amulet of glory/amulet of power)
Torso-black d'hide body (armadyl or karils would be better)
Legs-void skirt (black d'hide chaps/karils or armadyl would be better)
Gloves-barrows gloves (your best gloves)
Ring-Dragonstone ring (i) (your best ring)
Boots-jester boots (infinity boots are the same)
Cape-God cape (skillcape/oby cape/fire cape is even better)
Weapon-Zamorakian spear (godsword/dragon mace+rune defender/anchor)
NOTE:If you don't have 70 ranged and you do have void melee, you can wear that.
Here is a recommended invo:The slayer gem isn't necessary if you have a combat brace or don't care about checking your progress. Bring enhanced excaliber if you have one, otherwise a sgs or any spec weapon. An anti dragon shield is useful to protect yourself from the brutal green dragons on the way to the spot. Bring swallow whole scrolls for your bunyip if you have one, these allow you to eat all the raw sharks and lobster the waterfiends drop. A combat potion helps lots, I use it mainly because its cheap. You can use super atk/str if you like. At least 10 pieces of decent food should see you through when the waterfiends wont drop raws. A bunyip pouch if you have 68 summoning. Don't summon it until you are inside the cavern as you cant take familiars through the whirlpool. A unicorn stallion replaces the need for a bunyip.
Getting thereNow that your all suited up its time to go to the ancient caverns and kill waterfiends. Start by going to the pier south of barbarian outpost. Then jump into the whrilpool.
Now.....you should be inside the caverns. You're in a safespot...for now....
Be sure to have you anti dragon shield equipped and proceed down the stairs.....
Now..run west past the dragon to the main spot.
Now enjoy killing all those waterfiends! Heres some epic pictures of me!
When you're out of food make you hasty escape by jumping onto this log.
ENJOY!
Disclaimer:
This guide is pure opinion and should you die I cannot and will not be held responsible.
Also the gear I use may differ from my recommendation because I am a fashion freak.