What happens to Dying Light when the obsession changes?

After you kill the obsession and Dying Light activates what happens if a survivor uses Decisive Strike on you and they become the obsession? Is the action speed penalty still active?

Solution 1:

With the old Version of the perk, it actually resets to the point where the penalty for the survivors will be removed again, when the obsession shifts to a living one.

So No, the penalty will not be active until you have killed the new Obsession.

Its's the same as with "Rancor", which will let you kill the Obsession if the exit gates have been powered and will let you kill the Decisive Strike Survivor even if you already killed an survivor with the perk.

But since they apparently changed the perk with 3.2.0 it now gives tokens for hooked survivors while the obsession is alive.

As with any other obsession perk that gains, or keeps an effect after a certain condition is kept (e.g. Save the Best for Last). A new Obsession will reactivate the perk to the state before killing the obsession. So you will keep your Tokens as well.