The first issue for Dark Horse Comics and Mattel’s new Masters of the Universe & Teenage Mutant Ninja Turtles mashup comic series titled “Turtles of Grayskull” has not even landed in comic book stores yet, but we already have the exciting covers and synopsis for issue #3 to show you! Starting with the cover artwork, issue #3 will have three terrific covers to choose from, the main and two variants. Check out all three below: Main Cover Art by Freddie E. Williams II Variant Cover Art by Tyler Crook Variant Cover Art by Ramon Villalobos Now for the official synopsis! Warning: *Minor Spoilers Ahead* SYNOPSIS: The…