Many people struggle with the newly added "Inferno" and I have completed it over 30 times on maxed accounts, as well as on one defence pures. The only actual requirement is 43 prayer, and a Twisted Bow. I don't believe it's possible right now to complete with a crossbow/blowpipe.
The Inferno is a minigame where you can receive the Infernal Cape located in Edgeville. At the moment it is the Tzhaar NPC named "Start Inferno" when you hover your mouse on it. The objective of the minigame is to defeat TzKal-Zuk. He has 1200 HP and if you do not stand behind the huge pillar in front of your character when you spawn, he will most likely hit you for all of your HP.
Infernal Cape Stats:
99% of this Inferno is RNG based. EDIT: You can no longer teleport "::home" to get out of the Inferno. You'll have to die and respawn to try again.
These are 2 setups that can easily defeat the Inferno. I suggest using the BIS items you can to do this.
You will definitely want to use an Overload during this. They are untradeable, but you can buy them in the Player Owned Stores and at the Donator Zone.
You will want to pray range, and use the best offensive range prayer you can.
Before you start, make sure you overload and eat rocktails so your HP is it at the highest it can be. When you wear Pernix, and overload, then eat rocktails, your HP can get up to 162.
Starting the fight -
When you first spawn in, you'll want to immediately shoot twice. Do not move at all, just spam click Zuk. The pillar will start to move on the 2nd shot, but you'll stay protected.
The pillar will immediately start moving towards the right, so you'll want to click a few tiles before the end, and shoot again as your run the direction you clicked.
Now you're reaching the corner. You will want to stand on the 5th tile from the end, and shoot twice again. On your 2nd shot the pillar will start to move back towards the left, but just above you will stay protected.
Note: If you have reached this point, and Zuk is not below at least 1,000 HP, I suggest teleporting "::home" and starting over. You're not likely to hit enough before the minions will stack you out.
Now all you have to do is start moving with the pillar. There's not an exact spot to click, just try your best and don't lead too far or else the pillar will not protect you. The green highlighted area is where you should be clicking, and the blue highlighted area is where you should actually take a shot.
If I have hit this point and Zuk is above 900 hitpoints, I usually teleport home to try again.
In this picture, the green area is basically repeating the step above. You're just running to get in front of where the pillar will be when you actually shoot. The blue area is where you just took your last shot.
At this point, Zuk should be around 450-700 HP.
If you get to this point, have been hitting well, and Zuk is around 500 or so HP (hopefully lower), you've almost completed the Inferno.
The left side is just like when you were on the right side. You'll want to start on the 5th tile and shoot twice. Prepare to run towards the right now.
If you minions are already hitting you after you're shot twice and are about to run, you probably will not survive.
I usually finish the kill around this point. There are times when you'll have to move again with the portal, but if you have made it to this point, you should already know where you should stand.
Hopefully, by now you've completed the Inferno. CONGRATULATIONS
Beat my collection now