1. A not so common nickname given to Miyavi based on a type of photoshoot he did. In the photoshoot he dressed as a Jedi. Someone used the photos and made them into an animated icon with him in various poses. The icon said "Wanna know Miyavi's secret?......He is Darth Meevers."
Miyavi is pronouced ME-YAH-VE not MY-YAH-VE.
Miyavi likes it when his fans call him Myv, wich is pronouced MEEV, and is also how some fans spell Myv. Some times his fans like to give him cute little nick names like Meever, Myv-Myv, and The Myv. How 'Meevers' came to be I'm not sure. Possibly the creator of the icon felt like adding an S to the end.
2. This name has been used as a username on various websites and is spelled and witten out in everyway possible, so good luck stealing it.
Fan number one: "Dude, did you see that icon of Miyavi that says Darth Meevers?"
Fan numer two: "Yeah! He looks absolutely adorable. I love Myv."
Random Gaian: "Darth Meevers is the coolest kid on Gaia, betch"