Quickly after he arrived to play Lonny in "Rock of Ages," Mark Shunock fell in love with Las Vegas. And it took him only about three months to put together a charity that is prospering to this day: Mondays Dark.    Mark and wife Cheryl Daro call upon their performing friends every other Monday to put on a show, the proceeds benefiting a different Las Vegas charity every time. Since it began, Mondays Dark has raised more than $1.5 million.    While "Rock of Ages" is gone, Mark is best known as the in-game MC for the Vegas Golden Knights. He's the guy up at the siren keeping up the energy between periods. And he's now branched into boxing, as a ring announcer for Top Rank Boxing cards.    And, oh yeah: he was nominated for a Helen Hayes Award for his work in the national tour of "The Lion King" on Broadway!  Quite a bit, he says, for a kid from Sault Ste. Marie, Ontario!   Hosts: Jonathan Jossel, Lisa Melmed, Gary Vickery