File:Special Duration Up Vulnerability Chart.png

Formula
x = Ability Points = 10*MainSlots+3*SubSlots

A = % Change = (0.99*x-(0.09*x)^2)/30

Killer Wail normally leaves the player vulnerable for 120 frames, and Inkstrike for 100 frames as of 2.7.0. 60 of these frames are affected by Special Duration Up.

B = Killer Wail Vulnerability Time (frames) = 60+60*(1-A)

C = Inkstrike Vulnerability Time (frames) = 40+60*(1-A)

Killer Wail Vulnerability Time (seconds) = B/60

Inkstrike Vulnerability Time (seconds) = C/60