could you be more specific? does each level give the same upgrade (increase the number of targets) or do the levels give different upgrades?
The first case is easy... just change the Stats-Levels field to 4, and change the Data- fields for each level.
For the second case, you could have separate abilities for the additional upgrades that have the moon glaive as a research requirement (like the way druids of the claw have to research before they get bear form).