Shouldn't it be Cosmic Blade?

[Michael]

I thought Cosmic is the term for anything related to the Cosmos. Such as "Cosmic Balance"
Am I wrong? Because Cosmos Blade does sound better, do you think they picked it because it does? Or did the authors just didn't know the term Cosmic? Such as there are no Magisters at a Magisterium.

[Cynthia]

Maybe the Cosmos Blade is an object like the copper gauntlet. There really isn't such thing as the "_______" <- (forgot how to spell it) so maybe the sword (I'm guessing) is a type name for it. And a Magisterium is something from Ancient Rome, right? But I'm guessing that the term that were looking for was "magister" (which is another word for magician) and "ium" which is a suffix for metallic substances. Maybe they knew what a Magisterium, but in that case, they wanted something new entirely.