Vilgax and Ascalon
After the latest episode Solitary Assignment
We learn that you have to be deemed "worthy" to fully use the sword.
Obviously, Vilgax wasn't worthy. So he was probably tapping into Daigon's powers.
I'm just surprised that Azmuth didn't put in other safeguards on the sword. IE
Make it impossible for someone to lift it if they're deemed "unworthy." Especially after the fiasco on the other planet.
Just my observations.