I'll be blunt. It's where Attack on Titan becomes a story. There are definitely fans who don't like the new direction, but pandering to them would have doomed the show to never-ending mindless death. (Like a Titan, in fact.) If you want apocalyptic intensity and mega-gore, rewatch Season 1. It's brilliant at it. It's masterful at what it does. However the characterisation's pretty limited, the fan-favourite character (Captain Levi) is dull and the plot is mostly "death death death" (bar some admittedly huge twists). It's a zombie film, except that the zombies are so big that they'll crush your house underfoot before they eat you.

Here, all that changes. Our view of the world is flipped upside-down. We learn secrets that recontextualise everything we've seen. This is extreme enough that I wasn't sure I'd got my head wrapped around them and Tomoko was explaining it all to me (because she's read the manga). There's puzzling worldbuilding and weird mythology (foreshadowed in the Season 2 end title sequence). Are the SPOILERS attacking themselves? I could see a potential motivation for this, but I hadn't yet processed it properly.

Season 4 goes ten times further, by the way.

The plot's accelerating. Season 3 Part 1 compressed a manga story arc that even the author himself says had dragged on too long. Season 3 Part 2 is half Titan carnage and half long-hidden secrets. There's a battle to please anyone who'd been complaining about the recently lack of Titans, while also having mind-bending revelations. The suicide charge in ep.53 is powerful, all the more so for having a full episode's build-up. (The man who suggested it knew that he'd be leading it.)

The intensity builds further. Our heroes can make Titans and will get an opportunity to do so.

Bloody hell, the basement. (It felt as if we'd been waiting 56 episodes for that basement.) The secrets. The racists in ep.57. The history. You might need to rewatch episodes or do some googling to get it all straight, but Tomoko says that the anime's explanations are easier to follow than the manga's, with its bad art that makes it hard to tell who's who.

Very few shows ever achieve this level of game-changing... and it's not just a desperation ploy to keep alive a money-making franchise. This is how it's always been and we'd had no idea of the deeply weird truth. Eren's powers, his father, the Titan who ate his mother... it all fits. Ep.52 reveals a secret that's been hiding in plain sight since ep.13. If nothing else, this season makes the 2015 live-action films even more embarrassing than they already were. It's very good. Just don't expect a rerun of Season 1's horror. (Apart from anything else, anyone who's survived this long will have become a highly competent fighter who's experienced at killing Titans.)