Custom Disease Cloud

[PiesOfNorth]

I'm trying to make a spell that does AoE damage over time without killing those affected. As far as I know, the only ability that does this is Disease Cloud, but as others have reported, it seems no matter what you change the buff/art/effect to, an ability based on disease cloud is hard-coded to give the disease buff and the disease cloud art. I don't want to change gameplay constants, since I want the original Disease Cloud to remain untouched.

Is there any other way to accomplish this?