I think the reason why he wants to kill the 5 kages,he wants to rebuild the world as one and with only one leader,maybe himself..not because he wants revenge(maybe a little ^_^) he wants to reunite the world,same with naruto..but there is a different..in naruto's case,he wants everyone to understand one another,to have peace!in sasuke's case,he wants to lead the world and control it to become one!same resolution but different method..
Well for me sasuke is an idiot because if he will create a world like that then wouldnt the world be in the hands of one person. And if another person whos stronger than sasuke comes up he just need to defeat sasuke to rule the world and that is just idiotic
He says the 5 kages but Gaara is the same age as him Gaara has nothing to do with what the others did. In fact none of them except the Tsuchikage and maybe the Mizukage actually dunno but Gaara is his age he didn't shape that world.