Battle for Throne
When the Palace is in the Competing Status, any leader can send troops to the Palace and Catapults
When your troops arriving at the Palace, if the Palace conqueror is your ally, the troops will join to gurad the Palace or Catapults. If the Palace conqueror is not your ally, there will be a battle
When Alliance which conqueres Catapults is not the same one which conquers the Palace, the Catapults will launch great rocks to the Palace continously, and strike the guard troops deadly