WARNING: The following contains spoilers for One Piece Chapter 1040, "Wasted Words on Young Ears," by Eiichiro Oda, Stephen Paul, and Vanessa Satone, available in English from Viz Media.
One Piece Chapter 1040 saw the defeat of Emperor of the Sea Big Mom at the hands of Kid and Law after a long, arduous battle. This is a major victory for the Pirate-Samurai Alliance and for Kid, Law, and Luffy in general, as it means the three are one step closer to achieving their dreams. Despite the tremendous sigh of relief that our heroes should breathe, something feels...off.
The main power of the Soru Soru no Mi is soul manipulation, meaning that Big Mom can take souls out of a person and transfer them where she sees fit, as long as it's not to another person. It's how she created her Homies like Prometheus and Hera. She could also give up some of her own lifespan to heal her wounds. However, Big Mom never revealed her Awakened Devil Fruit powers, leaving the question of if she somehow survived the explosion that led to her defeat.
Before the events in Wano, Big Mom ruled over Toto Land, where she took a month's worth of soul from each person within her domain. It's safe to assume she used the majority of the souls taken to create more Homies, but it's entirely possible that she could absorb those souls herself. While she can't transfer souls into people or corpses, we don't know if she can absorb them to extend her own lifespan. She could use them to mend her broken bones and grow bigger and stronger, so her body might be the exception to this rule, especially if it's a part of her Awakened abilities.
It's also entirely possible that she's able to transfer her own soul as part of her Awakened abilities, basically becoming a Homie herself. If she found an object to transfer her soul to, this could be possible considering she can do it with other people's souls. But that leads to the question of would her Devil Fruit powers would transfer over as well. She most likely has some kind of backup plan in the event of her defeat to prevent her death, especially when several of her children can create things like Cracker's Biscuit Soldier puppets. If one of them creates a vessel, Big Mom could transfer her soul over to it.
Her son Katakuri is the Second-in-Command of the Big Mom Pirates and is an Awakened Devil Fruit user, so it's safe to assume his mother is one as well. There's also the fact we never saw a body, which always leaves the possibility that she did survive. Before the explosion, she seemed so sure that she would survive as if she knew something nobody else did. This thing could be that she would survive because of her Devil Fruit.
She's proven time and again that she has the ability to survive attacks that would take anyone else out. Even for a Devil Fruit user, she has proven more resilient than others. She is an Emperor of the Sea, so it makes sense. But there's this uneasiness about her defeat, especially since she never revealed her Awakened powers, even when faced with the possibility of death.
