Whenever I get to the late game (second island) I've usually destroyed one or both portals, just leaving the large one in the wall. I'm feeling pretty good about myself and the large army I've amassed, but then this hulking enemy goes through, and in a single punch kills two knights and their entire entourage. My towers aren't effective enough to take them out it seems, but i also can't recover from these attacks in a night, and then another one attacks, What's up..? Am I doing something wrong, or is t...