All the people saying Rokudo's power is fading have forgotten how the power works. The very first girl who fell for him, which started the domino effect that caused this entire plot, "got over" him and got back together with her boyfriend ages ago, though she still seems to crush on Rokudo from time to time.
Rokudo's power causes infatuation, but it doesn't stop people from forming other relationships. Bad women aren't bound to him. That isn't how it works.
Plus, a lot of us have been predicting this for a long time. That Rokudo would build up this harem because of the spell, but would slowly shed them one by one as he "fixes" their lives. That's basically what's happening now. I imagine, given this is a shonen, the ultimate lesson at the end of all of this will be, the power will eventually go away, but even though it's gone, it won't matter, because they all now have bonds of friendship and they don't need the magic. Or something to that general effect.