Tips:

I have completed this quest 3 times, always taking less than a week.  It seems that many people have problems collecting the items, so this is my attempt to help you through it.

• Try to do the quest when you are between 120 and 125, this way you will actually gain decent experience too.
• Don't bot, it is against the rules, and you can much more effectively manage  to collect items without staying in the same place.
• Maximize your magic defense for the first 2 stages, and when you are fighting satan.
• Convert your Moss, DreamGrass, SoulAroma to other items, because the other items can't be dropped if you are pk'd.

My Process:

I work my way around the map, from 1-2-3-4-5-7-8-6 and kill the 500 meter mob and the 20 meter mobs.  These mobs tend to drop the items much more frequently, but they don't respawn as fast.  Whenever I get superman, I kill whatever I can in the area.

The 20 meter mob spawns every 15-25 minutes after the last time it spawned, so you may get a double spawn if it has been a while (similar to snakeking).

After I make one full circuit, I go and do whatever summoning I can, then I repeat.  As simple as that.

Its fairly normal for me to collect 12-15 quest items in one circuit, which is often 200 kills or less.

Once I get to stage 2, I continue the same process, because those mobs bring the mountain down faster.  This stage goes quick, because you don't have to wait for drops.

Once I get to stage 3, I replace ears with a helm, and just go attack the Souls, its fairly easy and doesn't take that long.  If I have guildies around who wanna help, I have them go to the different souls in front of me and take their health down pretty low, so I don't have to spend much time to kill them.

Then I go kill a couple of 500 meter mobs to collect the squama bead needed for summoning satan.

For satan, I bring my reborn or 2d reborn friend with the most magic defense to tank.  (as a side note there is actually no difference between a reborn and a 2d reborn as far as reborn magic defense bonus)