In Revelation 13 the BEAST had 7 heads. A beast in that time could have symbolized and empire. Hence each of the 7 heads would have been separate entities, such as countries or leaders, We tend to assume that all the heads were evil because they were attached to an evil beast but that's an ASSUMPTION.
What if one of the heads wasn't evil and went rogue, thus they tried to kill it, imagine their surprise when it came back to life?
Just a random thought.