The circle with the line through it is a symbology you will see repeated in about every scene of very episode, once you look for it. It is the cracking of the second moon by a comet's impact and the fiery 'dragons' it is bleeding that fall to the ground. It is reinterpreted in many, many ways. If you watch carefully, every time a moon is cracked there will also be a shriek or cry and a head will fall or hang or a body will fall. That means literally every moon you can think of, esp if you hear a shriek...look for a cracking or cracked moon.