WARNING: All NPCs now have detect invisibility making this run MUCH harder.
Availability: 15-18 minute repops. 2-3 repops per 6 hours.
I would suggest no less than a form of 9. If at all possible you're going to want a Dracon or two, or people who can spam flame wind, 2 or 3 reliable tanks, and the rest should be healers. This run can range from 2 to 4 hours for 1 kill so be sure you can commit to it. You're going to need to be active for almost all of it because this run can go from smooth to over very quickly.
To start off the mighty balrog, Abacax you're going to need a light called a lucid dream. To get this you need to get 3 things.
Take these 3 items to the weapon's collector in Dungeon Avarice and give them to him in the order of candle, boots, sword. He will then give you a shimmering amber scale, which you take to the red dragon, who will then give you the lucid dream. Locker it, because it is essential to starting the run. After you have your formation head to Dira Temple in The Towne of Xaventry. Continue on as if you were going to the Dira priest (you should probably get the obsidian and ceramic keys to unlock the doors on the way before hand, their repops can add unnecessary time to an already long run). Spam through the dizzys until you come across a room named Hatred. Here is will you and your formation will spell up. Get ONE person wear the dream, and go down, you will instantly want to eat a calm mix because you've just summoned the Congress of Murder, you must kill them to open a portal to the domain of the mighty balrog, Abacax.
Items that help greatly:
Congress of Murder
The Congress of murder consists of 3 mobs, Heptheran the Demonic, Sargrag the sinner, and Torath the Damned. They are all formed and hidden, i advise that you reveal and spell each one up with curse, faerie fire, weaken, poison, and plague when possible. They do cast witch spells so be sure whoever is taking is ready for that. The trick to killing the congress is all about order, Start with Heptheran who has the lowest HP, and end with Torath, who has the most. During the fight there should be 1 bard slowing all 3 mobs. If anyone dies during the fight, do NOT loot unless the rest of the formation is still fighting the congress, or the congress of murder is dead. If you choose to loot while no one is in combat they will attack you each time you take something from your corpse. After they have died a portal will open up to the first room of the mighty balrog, Abacax.
This is where all the fun starts, it is a MUST that you have improved invisiblity on at ALL times. There are many mobs that form if you are not. It is also good to send in an elemental to see what you're dealing with before you enter. There is 1 mob, a lurking arthropomancer, that has detect invis. This is the mob to watch out for, all mobs here silently teleport into rooms. Arthropomancers summon scarab beetles, this is where your dracons or flame wind spammers come in to play, they should flame wind to kill off the scarabs during the entire fight to reduce damage to the tank. Beware however because the beetle's corpses do explode. It is a MUST that you be rested at all times and kill every tick you see, the ticks spook you and if you go east (FLOYD), you're out of the run. The next thing you need to know is how is area works. Here is a simplified map and key to show you the area. A is the mighty balrog, Abacax, R is Regen, N is NO-regen, S is a solitary regen room, E is where you entered from the portal. and every X is the same room, X also brings you back to E every time, and is regen. So if you go east from the mighty balrog, Abacax's room, and go west, you'll end up back at E.
When you start at E the door north may not always be open, doors open and close every 15 minutes (1 in-game hour) in this area. You must wait for the first north to open to proceed anywhere, its best to clear both E and X and wait in X for the first north to open. Kill as many Arthropomancers as possible do you don't have to deal with them later (hopefully). There is a bit of strategy involved in moving through the rooms on the way to the mighty balrog, Abacax, it is wise to check an in-game watch whenever a door opens (you should see an emote) and write down the time. Now you want to spend as much time as possible in the regen rooms so here's what you do. After you've written down the time that the first north opens, head in and clear out any arthropomancers and ticks, rest and heal/spell up. Now you wait for the 2nd door to open, Once it does the south behind you will close and there's no way back if you get spooked out or decide to go out (as in go east). Instead of going north right away, its best to sit in the regen room until about 10 IN-GAME minutes until the next door will open, be weary because the time the doors open tend to change by 3-4 in-game minutes, in either way. Once you've reached that time head north and wait for the door to open and go north again, back into regen. Be careful while doing this, if you wait too long and the north closes for you, you can either wait 2 hours for it to come around again or leave. Rinse and repeat this process, killing all ticks and arthropomancers along the way untill you get to see the mighty balrog, Abacax north of you.
The mighty balrog, Abacax Encounter
A few things to remember, he bite paralyses, dispels, can bolt for around 2000 damage, IS counterspellable and blindable via flash bombs. The room is low regen with a shutting south door and the none pk up is one way exit.
Once you get to the mighty balrog, Abacax check to see if there are any arthropomancers, if there are wait as long as you can before you have to go in. Killing the mighty balrog, Abacax itself is actually very simple, be sure the tank has enough hp to tank bolts, have someone spamming counterspell, and have another throwing flash bombs untill he's blind. Be sure to spell him up with all the regulars, ff/curse/slow etc and get the job done quick. IF an arthropomancer decides to show during the fight he WILL form on the mighty balrog, Abacax, if that should happen be sure you have everyone switch to the arthropomancer and kill it quick, also be sure to keep the tank healed. After he is dead be sure to rest/kill off any ticks to wait for repop, when you've killed him as many times as you've pleased, you can head down into the recall of Shadow Castle.
Note: Whoever lands the killing blow will be granted the Mark of Lethargy, there is now a 50% chance the entire form will receive the mark.
The mighty balrog, Abacax carries: