Castle Invasion: Throne Out

The King's Dragon is the boss of level 10. His main attack is moving around the screen before starting to charge at you in a straight line. To stop him, you just need to hit him with a few shots before he hits the castle and he will move back again. His next attack consists of him calling a few regular enemies out and then leaving the screen only to reappear (normally at the very top or bottom of the screen) charging at you. Just hit him with shots until he backs off and take out the regular enemies. He will keep repeating those two attacks for a while before adding his final attack which is where he will stop and fire a flame ball at the castle. Just shoot the flame ball before it hits the castle in order to stop it. Just keep attacking him until he is defeated and the trophy will pop afterwards.