Indulge the speculation:
Let's assume the bubbles are tied to the island and will stop functioning if the island is damaged or they leave.
Let's also assume Devon copies Saturn so the Seraphim follows her as they leave.
Now the crazy part. Let's Imagine Laffe betrays Teach, hypnotizes the Seraphim, and takes them to MJ.
At this point, Laffe is revealed to be an undercover agent with mixed loyalties.
Why you ask?
Remember Nami's plotline going back to East Blue?
Remember Laffe is the navigator for his crew
Remember the forum doesn't want Nami to fight a man?
Remember every Yonko Crew so far has had a traitor among them.
Remember how easily Laffe gets into WG facilities.
Remember how Laffe has wings, which tie him to the Heaven's?
Remember how Laffee was a Demon Sheriff because he used his position to be cruel like a CD.
Remember how he sneaks around like a CP assassin?
Of course, this is all speculation . . .
