Wondering what was the toughest RPG you ever played? Was it Dark Souls? Legend of Zelda 2? What was it?

My my pick is the 7th Saga by Enix. The game itself isn't tough until you meet up with a rival, they are levelled a few levels ahead of you and tend to hit your weakness every shot. You can't grind to beat them as they will level too. It takes a lucky shot in those battles to get through them if you ever do get through them, and it is my pick.