I've played all 5 at some point. I started the game on wind, then I got Mei and changed to water. After a while, I changed to fire. Then I got Edo Deidara and changed to earth. And I have a second character that has been lightning the whole time. And I can tell you that which main I chose has little or no impact on how I did in spacetime/Sage/GNW. All the mains have their strengths and weaknesses. If you are thinking which main is the best and what team can I build for that main, then you have already lost. Look at your good rare ninja, and build a team of 3 for them. Then look at what you team is missing and choose your main accordingly. Don't try to shoehorn your team into a main, pick a main that compliments your rare/ultra rare ninja.