Quote Originally Posted by Frozen_Feet View Post
Level 6 ESPer is nothing but a wild dream, for now.
Level 6 ESPer may be a dream period. One hasn't been seen at all in canon and the Level 5 Esper closest to it still had to kill 10,000 Level 3s before he was supposed to be a Level 6. This same guy split a continent.

In other, more practical, terms the levels are only 0-5.