The Catalyser
In Greek mythology there are five rivers that flow through the realm of Hades, the God of the dead. Before reincarnation souls are made to drink from Lethe, the river of forgetfulness, thus preventing them from remembering their past lives and their current life purpose.

Rune of the balance and justice ruled from a higher rationality. The rune of sacrifice of the individual (self) for well-being of the whole (society).