-Crobat is something that is a rather nasty issue for Roserade and also for Heracross, as the only way of safely dealing with it a stone edge and as we all know it is prone to miss.
-Entei can cause issues for the core on it's own with no real switch in and with it taking out either Roserade or Heracross Sharpedo isnt reliable enough to switch in properly esp with chances of getting burnt are high.
-Mega Aggron is well the Physical wall of UU and with Filter to make Close Combat do even less that it should Sharpedo can't touch it either.
-Any Intimidate users, just a -1 Atk cripples this badly.
-Other Scarf users, especially anything that has base speed 95 or higher. eg: Darmanitan, Infernape, Salamence.