Straight to the Point
At the end of "Dead to Rights", it was revealed that Malcolm Merlyn spent 2 years in Nanda Parbat. It just so happens that in the comics, Ra's Al Ghul's story arc occurs in that fictional location. Meaning Ra's Al Ghul trained Merlyn for two years, perhaps in archery is unknown. If Ra's Al Ghul does appear, maybe there might be a reason for Batman to show up too! Although unlikely, due to the introduction of Nanda Parbat, Deadman may appear on the show, or at least his human [alive] version, Boston Brand.