Finished form as of June 2010 update:
DMG: 98 Delay:480
DMG +3 Delay +12
Additional Effect: Weakens Defense +15.
Seems to proc at a noticebly higher rate then Thalassocrat/Mezraq evasion down.
Procing once every 2-4 hits. Granted the effect isn't already on the enemy.
This is currently also the best
polearm for a Drg right now.
The highest level of Oathkeeper is dmg 101 Delay 492. And since the next level for Oathkeeper is Rhongomiant (good luck ;-;), you're better off going for this thing. Same stats with the bonus of Weakens Defense +15.
Whether the 15% from this weapon stacks with the 20% from Angon. I am still not sure of
EDIT: Confirmed that Angon will not overwrite the Defense Down effect from this weapon. Nor will it stack with it.