The third season of Attack on Titan focuses on what's left of Levi's squad. They're now considered enemies of humanity by the King and the Military Police for knowing too much. Much of the first half of this part of the third season involves Eren and company fending for themselves while we are introduced to a couple of crucial characters. Rod Reiss is a figure from Historia's past who much of humanity's plight can be attributed to. Kenny Ackerman doesn't just share a name with Levi, but the same dangerous combat skills that prove a match for the squad. Needless to say, both Rod and Kenny are part of some spectacular revelations regarding why humanity even resides within walls.
There is more of a focus on human-on-human combat during this season, but that doesn't hinder the animation whatsoever. The early major fight between Levi and Kenny's own crew within the walls are some of the best of the year. Eventually, certain events turn the tides and the people toward the Survey Corps' plight and the goal shifts towards harnessing Eren's abilities, both old and new, to help fix the walls. If you're familiar with this arc from the manga, know that the series moves at a much more brisk pace and is all the more better for it. Unfortunately, the series' MacGuffin, i.e. the contents of Eren's father's basement, will have to wait until next Spring as the series takes a hiatus.