10. So, Dany WAS Mad, Then
In the wake of the penultimate episode, there was some speculation that Dany hadn't actually become the "Mad Queen" and that her reaction was merely a human response to what she'd been forced to go through. Even some of the cast echoed that sentiment and the finale doubled down on the notion, exploring - through Jon - the idea of her being a product of her experience.
But there can be no doubt that the correct way to think of Dany was the way Tyrion did. Yes, she was led to her mental state and to every decision she made in King's Landing, but that didn't mean she wasn't also the Mad Queen. And Dany herself affirmed as much in her final interaction with Jon and her rousing speech to the Unsullied and the Dothraki.
That speech in particular was not merely one of a vulnerable, emotional victim, it was her war cry and her setting out her intention to continue to wage war under the guise of freeing the world. Her targets are named - from Winterfell to Dorne, Lannisport to Qarth, the Summer Isles to the Jade Sea - and her intention (to "break the wheel") has been warped by her belief that her agenda is righteous no matter what the cost to the innocents.
As Tyrion tells Jon after his arrest, Dany was molded into her image by the advisors who sought to make a Queen of her. She was always fire and blood, but they helped spur her on by cheering every time she used death to advance her cause. It was inevitable that she'd see that as her means of "liberation."