A master of unarmed combat must wear gloves to conceal his glowing hands.
Zig Zagged: There's a fifteen-page-long chart explaining how effective weapons with different glow intensities are against one another. And the authors still manage to do a complete Ass Pull every once in a while.
Glowing weapons are purely aesthetic.
The weapons do not glow at all.
There are no weapons.
Enforced: The toy company handling the merchandising wants to make all the best toy weapons glow in the dark, so the producers have that incorporated into the strongest weapons on the show.
Exploited The heroes use their weapons as flashlights when they need to find their way in the dark.
Defied: "Target their leader! The one with the glowing sword, kill him first!"
Discussed: "Yes, you're exactly right: The glow is due to phlebotinum dust used during smelting to increase strength."
Conversed: "What's with all the glowing swords? Is this a skirmish or a rave?"
Deconstructed: The most powerful characters are all blind. What was the audience expecting, to be able to see after that ultimate attack that's rated at 47 million Candela? Furthermore, the energy loss from the glow turns out to be a major waste of energy, as a similarly-rated sword that was forged from a light-absorbing material can do the same attack better.