While my only attempts at the dragon fight had been on easy (everything up to and including my first few attempts at the second last battle (without the soul forge repair) were done on normal), thanks to getting invis on Astarte I managed to down the dragon. I actually entered combat early due to some bad character movement, but once things were underway it was like defeating the guardian statues in Hunter's Edge using just summons, about as quick as beating a gorilla to death with a feather.