Nagato was so powerful in the past and was very strong minded base on his dream to change the system.Sasuke on the other hand had similar feeling since his clan was destroy for konoha glory,as a result Sasuke currently determine to change the system
However these two got trolled in the worst way possible from my view.Nagato who was heartless and even killed his senesi (Jiraya,someone he was very close to) got TNJ by someone he new for about 30 minute in pein invasion.Sasuke on the other hand ,had susano,raiton defense and other possible jutsu he can use against Madara in their final encounter ,but he got stab by his own sword to his heart.Sasuke survived 2 blow from raikage,multiple stab by killerbee,C0 bomb impact from dediara etc but he die to a stab
However these two got trolled in the worst way possible from my view.Nagato who was heartless and even killed his senesi (Jiraya,someone he was very close to) got TNJ by someone he new for about 30 minute in pein invasion.Sasuke on the other hand ,had susano,raiton defense and other possible jutsu he can use against Madara in their final encounter ,but he got stab by his own sword to his heart.Sasuke survived 2 blow from raikage,multiple stab by killerbee,C0 bomb impact from dediara etc but he die to a stab