Here's my theory: the cube is water from the Rhine River, which was worshipped by the Franks, who were Germanic pagans that worshipped Odin/Wotan. The Franks conquered Gaul, which became France, hence the spelling of Phranque.
The sparkly thing inside the cube is the Rhinegold ring from Wagner's Ring Cycle, stolen from Alberich the dwarf by Wotan. Odin probably is in the Everwhen and is looking for the ring.
Laufey will probably defeat Odin and use the ring to take control of the Everwhen, ruling from a location called Avalon. Her magic will be revealed to be fairy magic, or Faye magic, and she'll become the Queen of Fairies or the God of Magic.
Faye will remain in Everwhen, but will be able to communicate with Kratos and Atreus through water, becoming known as the Lady of the Lake.
Atreus' solo game will be Celtic and probably feature a Merlin mentor character. Faye (Morgan LeFaye?) will give him the sword through water to use. My guess the reason the ribbons talk instead of the sword is so that the ribbons can be removed before giving it to Atreus. The sword is probably some powerful artifact god killer that becomes Excalibur.
The most famous figure in Celtic mythology is the Morrigan, the Irish goddess of war, fate, and death. She often appeared as a crow or Raven, and at other times as three sisters. She is the wife of Dagda, the chief father of Celtic pantheon. Sounds like a strong concept for antagonists.