Well if there is someone stronger than kaguya it's not that hooded dude at least not how he is now naruto blocks his atk with his chakra cloak neg diff and sasuke looks prime to do some dmg to him although kishi seems to be nerfing them both naruto and sasuke easily be able to take them especially if they're together
To see the future, the past is handy to know.
Black Zetsu had Madara had Obito form Akatsuki to gather the Bijuu in order to revive the Juubi with the very end result being Kaguya. The long and the short of it is that Akatsuki was a trigger that enabled Kaguya to be revived so when we look at the bigger picture, Akatsuki is a means to an end.
Let's take one angle; this man isn't an alien. Following along with that train of thought, we know for sure he wants to rebuild Akatsuki and that possible greater threats have been hinted by Sasuke. It is possible that This man wants to retrace the original steps of Akatsuki, but it's also possible that he wants to bring greater beings to Earth but doesn't yet have the power to do so, despite having the ideal teleportation ability - Kamui. To travel within Kaguya's cluster of "homemade "dimensions was immensely difficult for Obito and Sakura, despite having the great chakra of the Byakugou.
So its only natural that the world/dimension that was Kaguya's original home could be much further away than her own artificially created homes.
The new Akatsuki could be formed as the "mean" to open access to earth for other aliens.
