This is the result of too much free time.
Anyone who has DRK might be interested in reading this. It basically gives a run down of zerging damage.
ALL OF THE DATA ASSUMES YOU HAVE CAPPED MAGIC HASTE (2x Soul Voice March + Haste) Which will give you 224/512 = 43.75% Haste.
Some stuff to keep in mind: These values are mathematically calculated, and will not correspond to actual values 1:1, but they should overall give a grasp of "In a perfect situation" to help you figure out what the best option for gear is to use in a zerg.
It covers Kraken Club, Bahamut's Zaghnal, Fortitude Axe, Rune Chopper, Ridill, Mercurial Kris
http://tubbers.livejournal.com/7576.html
This file will allow you to check your own zerg damage based on pDIF, HP, and Haste %
How to interpret the final 3 graphs:
There is a min-max range depending on two major factors: Equipment haste, and pDIF, the lower line is the minimum damage possible assuming all hits connect within the 30 seconds. Simply choose the weapon (They are color coded) and your Zerg HP, and based on what you think your pDIF will be you can get a very good estimate of the damage based on those two lines.
Hopefully you'll find it helpful if you are a DRK. It's pretty wall-o-text so beware.
Cliffnotes:
Need SV Dual March + Haste + Hasso + Desperate Blows (3 Merits)
Best Zerg Weapon (Assuming Homam Hands, Legs, Feet, Swift Belt, Walahra Turban):*
2500+ HP = Kraken Club
2100-2500 = Too close to measure absolutely.
1800-2100 HP = If you have SV Dual Minuets, Rune Chopper, otherwise Kraken Club.
1800+ HP 25% Haste Equipment (Dusk Gloves +1 and Speed Belt needed) = Kraken Club
*Not exact values just eyeball estimates
Edit: Fixed link
XI Wiki

