Here is the current drops for Morroc. Divide by 100 to get the percentage chance for the drop. Thank you for your patience.
(Edit: you can check my work below, but here's the tl;dr ) I'm convinced the drop rates are not what you've posted. Maybe the event doubles the previous rate (0.01%)? Please check again, and check what the event (and spotlight?) does.
I just went down to DG today. I got 8 cursed hands, 3 skin of ventus, and just 1 diabolus ring. I killed at least 1200 angels, golems, and humans, and about 700 spirits. The majority of the time I was using HE gum.
I did some statistics based on those drops you posted. The drop rate should be about 0.40% with all modifiers included.
0.05% * 2(event)*(1 + 1(VIP) + 2(HE gum)) = 0.40%
chance of getting 0 diabolus manteau from 1000 kills: 1.18%
chance of getting 0 or 1 diabolus ring from 700 kills: 23%
changing the modified drop rate to 0.08% gives about:
chance of getting 0 or 1 diabolus ring: 90%
chance of getting 0 or 1 diabolus mant: 75%
Those numbers seem a little more accurate.
Edited by squirreI, 30 November 2016 - 02:45 AM.