The phrase “you can’t beat someone at their own game” has never been more true, in my experience, than for Dave Guskin.  I’ve had the opportunity to cover Riftbound: The League of Legends Card Game since its inception, first traveling to Riot Games’s office last year before its October debut to get an early look, and then covering each expansion since. Every time I’ve spoken to lead designer Dave Guskin, it’s been over a few games of whichever set is…