Hades is the ruler of the Underworld. Charon (not a god) ferries the dead across the river Styx into the Underworld.
Hades' Allies are the Gods and Goddesses; demi gods and goddesses that dwell with Him in the Underworld. Persephone, Charon, Hecate etc.. If you are asking what Hades aliases are; He goes by Pluto, The Unseen one, The Rich One, Aides and more.
Charon, the ferryman of Hades
Hades has a boat full of Charon.
Charon was the ferryman of Hades.
Charon.
Charon, The Ferryman.
His name is Charon.
For more or less the same reason Hades himself was: it was his job. If there's a river that you can't ford or swim across, there has to be a ferryman. Charon was that ferryman.
The only things I can think of are: They are both Olympian Gods and hades was Athena's uncle.
Charon
Charon .
The ferryman in the Underworld is known as Charon.