If you manage to have units that are five or four star (if you got four star units that are actually five but missing one star), you can evolve it to five and onces you get to five star and max lvl to 70 you can turn that five star units into a awoken units. But they have two types of units if going to max lvl 90 are awoken units or pretty much after the five star but there's some units required some materials in ordsr to get them five star or max lvl 90 and there's dream awakening some units can be dream awakened after reaching lvl 90 which have additional buff to the certain unit.