How do you level up on fusion fall

Beat the fuse monsters that look like your favorite characters. Then, YOU GET A NANO OF THAT CHARACTER!!!!! :P
For every nano you get, you go up a level. So some one who is level 15 has 14 nanos. [Since when you defeat Fussion Buttercup you don't gain a level]


If you do not defeat a fusion in a nano mission, you do not gain a nano or a level, just a reward.