While we can all agree that the Battle of the Bastards was one of the best sequences on Game of Thrones ever, the season finale of Game of Thrones showed us that it was only the beginning. And when wildfire literally blew up the sept in Sunday's episode, it had fans wondering, is Cersei behind the fire on Game of Thrones? Because everyone knows that she had everything to gain by the deaths that resulted from that well-carried out explosion. The sequence of scenes at the start of Season 6, Episode 10 of Game of Thrones was played out very slowly and carefully, ending with Margaery insisting that everyone flee the sept because she could actually see that something was wrong. Which is so was. And what followed was that neon green wildfire igniting in the basement and blowing through the sept, definitively exploding the place and everyone in it.
These are the same people who were about to put Cersei to trial and probably sentence her to death, since the evidence against her was pretty hard and had piled up enough to condemn her. So Cersei had nothing to lose and everything to gain by arranging to have the fire started on Game of Thrones. And it makes perfect sense, since it was just in Episode 9 of Season 6 when we saw Qyburn and Cersei whispering about a certain "rumor".
That elusive rumor was so obviously the gigantic stash of wildfire hidden beneath the sept. Had Cersei not arranged with Qyburn to have the wildfire blow up the sept in an explosion to be remembered on Game of Thrones, she would have probably lost her trial and that would have been the end of her. But we couldn't have that, right? As bad as Cersei is, she's also a necessary evil on Game of Thrones that we aren't quite done with yet.
So, is Cersei behind the fire on Game of Thrones? There isn't anyone else who could have or would have taken it upon themselves to blow up the sept in King's Landing. Remember how the zombified Mountain stopped Tommen from leaving his room at the castle, as Cersei sat in hers, keeping watch out the window? It was her way of doing what she could to save her son from the wildfire.
Of course, it's hard to say now what is going to happen to Cersei and the rest of King's Landing, especially once Jaime returns home to find that everything is pretty effed up now. But he loves Cersei, so it should all be fine, right? Right?