I'm thinking having the ability to define a stage where the dark doesn't hurt you, and one where it does.
Could be that at the start of a pack the darkness doesn't hurt you, but as you progress it begins to, then eventually you reach a point where it once again doesn't hurt you.
Could have it possible to define a priority, so that the stages don't overlap (say the initial darkness hurts you stage has a priority of 1, and the darkness no longer hurt you stage have a priority of 2, which then cuts out the first stage when you reach the second).