How is Levi so fast when attacking the Beast Titan's nape in season 3 part 2? In episode 17 of Attack on Titan season 3 part 2, when Levi takes out the Beast Titan's arm, eyes, and legs, Levi is in the air above the downed titan. When Levi goes for the kill, Zeke says that he doesn't have enough time to harden his nape. (YouTube video)

Levi was in the air, reeling in towards the Beast Titan. The ODM wire was still taut but the ODM gear was set to reel speed. It's demonstrated time and time again that when people using the ODM would listen to the order from the captains/whoever was in charge, they all move at the same speed and don't seem to rehook. They just stay there.

We saw Annie/the Female Titan harden quick enough to be protected from Oluo which was really fast.

But back to Levi, there wasn't any tall freestanding objects insight, so how did he move so fast? Please don't say it was gravity. He wasn't falling, he was reeling.
First : He's using more gas. as Mikasa did in S1 E7. I pinned. but how they can using more gas? there is no valve as you can see in the pictures I've pasted. I re-watched the Episode 7 and 8 from Season 1 multiple times but they said :


  No one knows how the ODM works except engineers



so I only can guess maybe they hold gas fire button(as you can see in the second picture there is two button on the handle , bottom button is for using gas) for long time or maybe push it rapidly or push it with more power. I really don't know and I searched whole of the internet and it seems no one knows :-D 



And this is how ODM is work.






Second : He's an Ackerman as it explained here :


   The Ackermans have an "awakened power" displayed by some members of the clan. Levi Ackerman describes it as "knowing exactly what needs to be done, and it lets the Ackermans exhibit physical abilities far above the average human. Eren Yeager learns from Zeke that this is because they were the result of the old Eldian Empire experimenting with the Subjects of Ymir. They can manifest the power of the Titans as humans, without becoming a Titan or inheriting any of the Nine Titans. When awakened, the Ackerman gains the battle experience from every single Ackerman before them via paths.



You also can watch this video at 3:40 for proof the ability of Ackerman clan or Ackerman family