Metal Allegiance, the metal supergroup featuring core members David Ellefson (Megadeth), Alex Skolnick (Testament) and Mike Portnoy (The Winery Dogs, ex-Dream Theater), along with multiple special guests, have premiered a new video for their cover of Dio’s “We Rock” featuring Mark Osegueda (Death Angel), Chris Jericho (Fozzy), Tim “Ripper” Owens (ex-Judas Priest), Alissa White-Gluz (Arch…