Miraculous Ladybug Theories

Master Fu takes the miraculouses back?

In the upcoming episode Feast Master Fu's past supposedly takes back the Ladybug and Chat Noir Miraculouses in hopes of protecting Marinette and Adrien of his past.
I've heard that we'll see some more flashbacks of Master Fu's past. And how he is worried that the people that stole the Miracle book and the butterfly and peacock miraculouses will come back to harm people. Most likely Marinette and Adrien.
He may use the miraculouses to experiment to find ways for the heroes to fight Hawkmoth and Mayura.
Or he could be using them to fight by himself against Mayura to fix what happened in his past. But with his strength as it is he would need a potion to make him stronger since he's 186 years old and is not as strong as he once was.
But he could die from this in which he would have to train someone to be the next miraculous holder which needs to be someone who he trusts and knows about the miraculouses aka Marinette Dupain-Cheng.