Honestly, when I first saw the stat distribution of Volcanion I immediately thought Heatran? He has better defenses then heatran at the cost of Hp and if it gets Stealth Rock I am sure there will be many that use him as a pseudo replacement for Heatran. The biggest attraction to Volcanion is likely gonna be his ultra Scald that makes peoples complaints of scald last gen seem funny. I think he will get a unique ability like Diamond Skin but beyond that I am unsure however, giving it flash fire seems kinda like a waste due to his already formidable 4x resistence to fire. I can see a scarf set being viable on him pending on his movepools coverage as ScarfTran is already formidable as is, however, this is just theorymoning so i will stop at that.