Not technically part of the Rhine!
Southern Judas Island is a large island to the far southwest of Centralia Island. It is a one months' journey by boat to the island.
Southern Judas consists of four kingdoms and a free-trade town that is without government. The four kingdoms each have one castle which is the seat of government. White Castle is on the western shores of Southern Judas inside the kingdom of Whitesnake. Green castle is the ivy and pricky flower covered castle that represents TeslaHome in the southeast of Southern Judas. On the north end of the island is Black Castle of the Judas Kingdom. Finally there is Metallina which is name to both castle and Kingdom.
The main kingdoms of Southern Judas are currently overrun with the undead. These undead were once the minions of the demoness Ryouko, but became free roaming creatures. Only Southern Judas (the nameless, freetrade city) survives. If not for its essential trade position, it too would have been abandoned. Instead a 30 foot wall was erected that seperates Southern Judas from the Necropolis (what locals call any part of the island on the other side of the wall).
There's also a rumor of orcs that live in peace with the undead. These orcs are occasionally bought as mercenaries. The last time they were used was by Benares (a liutenant of the demoness Ryouko) during the destruction of the four kingdoms. The orcs are mostly interested in looting and make a poor army. If the orcs are alive it is assumed they are still looting the great castles of Southern Judas.