Stringed Curses

"If you believe your weapon wants to end all existence, then so it will." -Daryun

After a killing blow you empower your warpick with the soul of your enemy granting an additional die of necrotic
damage, according to the slain creature's CR.
(0-2 is 1d4)(3-5 is 1d6)(6-9 is 1d8)
(10 or greater is 1d12)