Solvane and her chain

So, I just got to chapter 700 and something didn't leave my mind

How did Solvane's chain, imprisoning Hope, broke if Solvane never died?

At least, in the current timeline she only died after the raid of the Fire keepers with Sunny

The wooden knife was never used until the present, so how did the chain break?

The only thing I can imagine is that with maybe the death of the other 3 (Noctis, Sun Prince and Sevras), having only one chain remaining, Hope got enough of her powers to break the last one by herself?