I think when we get stronger, our jutsu should get stronger as well. For ex: Katon Goukakyu(fireball) should get bigger when we get stronger. It can be like if u have 4k nin, then it will increase a tile, and the next upgrade could be like at 10k, and so on. There also should be a limit so it doesn't get as big as a whole friggin' village. For homings, when we get stronger, they should get faster and MAYBE increase a tile. Just an idea............
