Hera: The Sword of Rhin/The sword of Rhin

A guard in Castle Venipanor said to ask the nomadic Rovers about the sword of Rhin.

The nomad camp
The nomad camp moves around the lands of Hera. It starts near the ruins of Irray, but it can move anywhere else, from Helwan to Rara Avis.

Because of pirates, leave your submarine near Castle Lunca and use the boat to look for the nomad camp; the latter is easier to retrieve, if a pirate steals it.

Ask Peggy about the sword of Rhin, and she will be willing to trade it for the most expensive item in Hera: Wanda's furs, that cost 5000 Gold.

Final grind
You need not only 5000 Gold pieces to obtain the sword of Rhin, but also an Agility of 90 to wield it!

Get onboard your ship or submarine and grind enemies with your cannon fire. A good location for grinding is the bay south of Helwan; the many corners allow you to easily get the first attack when you approach a land enemy.

If you reach the required agility before collecting the required gold, the best place where you can steal gold is Castle Thierry: there are 14 chests beyond the force field and 6 beyond a locked door.