Lethe.

Eyes closet to symbolise forgetting According to Ovid the Lethe flowed through the cave of hypnos, god of sleep so she has his headwings The Orphic religion said that it was passed under a cypress tree

Phlegethon

River made of Flames Dante wrote its made of Blood so her eyes are bleeding Since the Phlegethon is said to flow into Tartarus, and is often associated with torture, he holds a Whip/Snake

Cocytus River of wailing, the reason for the sad theatre mask and tears According to Dante it's Frozen

Styx Gods and people swore on the Styx since he was the goddes of oaths, so she holds a hand out Charon often is said to ferry the dead over the Styx, so she holds his pole Sometimes named as a daughter of Nyx, the Night, so she has Stars in her hair and eyes aswell as moons

Acheron

River of woe so she cries, and has wild hair and only one eye In paradise Lost it's said the rivers water is black, so her tears are Charon is also often said to ferry the dead over the acheron, so she holds his pole aswell. Her son Ascalaphus told the other gods that persephone had eaten promegranate seeds, so she hold one Usually described as a man, but rivers were often female and so I changed that to better fit with the other 5