Charon had a Second Generation ability that allowed him to absorb and accumulate kinetic energy into his body from any attack that hit him. He was able to transform this stored power into thermal energy to attack with.

How strong is Charon Hades?

At 75% max HP and 45% max HP, Charon will shatter two of the golden jars, destroying the player's cover from his attacks.

What happens if you beat Charon?

Defeating Charon will reward you with a 20% discount on the item shop. You will also earn the gold you borrowed from Charon. You will be teleported to the next chamber where you get to fight a mini-boss if you have enough health left. There are decent rewards after beating Charon in Hades.