UPDATE: This issue should no longer occur. Players who were affected may still be missing currency and/or unable to spend Auric Cells. We are working on a solution to resolve this and restore missing currency, and will update you as soon as possible.
Dying Light suggestion
It seems to work very well with Thanataphobia and Sloppy Butcher.
However, it should keep working with the stacks you already have after your obsession is killed. Just like Save the Best for Last does.
It already gives your obsession a massive altruism boost and the obsession even affected by the slow down while alive either.
So you are punished by losing your perk if you kill the obsession, but you are also punished for keeping your obsession alive.
It could also be 5% or 6% per stack so you don't HAVE to stack it with Thanataphobia.