Lazy Lazy writing... You can tell they are going more for spectacle than story in this season. Really stupid scenes. Fine you wanted to show us one of the dragons being killed, couldn't you make it more sensible?There are quite a few ways this can end.
Sansa takes the throne because dani dies.
Jon takes the throne because dani was killed in battle or by varys because of sansa.
Dani takes the throne and jon goes back to the north.
Dani + Jon rule together.
Cersei wins and keeps the throne.
Somewhere Jaime kills Cersei.
Bran raises the dead again and no one gets the throne.
I like wondering, but I'm happy to know that I'll know what happens within the next 2 weeks
And they are really building it up to show Dany getting crazy with rage. Basically they killed her dragon and Missandei in one episode to build that Dany will become mad with rage and become her father. Height of lazy writing will be them then showing Jon having to turn against Dany to save the people. But they are really digging themselves up that hole and there seems to be no other way left for the writers to take. So here's a prediction, Cersei is gonna be dead AND Dany is gonna be dead by the end of this season. Jon may become King OR just to instill some sill surprise they will find some minor character becoming King with Jon going back to the north / with the wildlings not wanting to be king.