Here's the idea.
Corrupt weapon has the negative VFX on default. Which is cool.
The idea here is to change the VFX of Corrupt Weapon with lvl 20 BG (aka Unholy Accuracy) to the one that Summoned Cornugon has for example? (Purple flames) insteads of usual negative VFX - to add some more "effect" to the fact that it's deep BG?
Just an idea