Necropolis or Castle (Which one is stronger?)

What's there to say? Of course, it's silly to compare two Castles without considering the circumstances. It all depends on the players. Whoever plays better will win, regardless of whether they're playing as Castle or Necropolis.
But if we're talking strictly about the characteristics, and not the players' abilities and skills, then it's hard to say. They both have their pros and cons, and the players have to choose for themselves.