My hardest RPG bosses would have to be in this order
1. Emerald Weapon-Final Fantasy 7
2. Ruby Weapon-Final Fantasy 7
3. Xenosaga 3 last boss I can't remeber it's name
4.Xenogears last bosses
That is all I can think of right now but I remeber catching so much hell from this bosses. What are you Hardest RPG bosses leave comments please and Happy Gaming!!