The 5th step of the quest requires 100 kills and 3 public event completions in the new zone, this case being the pale heart. However, due to the new format of public events being the overthrows the game doesn't recognize any "public event" completion. Neither the full completion of the overthrow or any of the smaller events therein count as a completion, therefor making the quest incompletable. This needs to be fixed, an idea being that each tier of the overthrow completion counts as a "public event".