How did the soldier commander become disabled?

Captain Levi did not die in the end, but he was injured and disabled. He lost the sight in his right eye and became disabled in his left leg. He has relied on a wheelchair since then.

After capturing Zeke, Levi inserted the thunder gun into his abdomen. If Zeke makes the slightest move, the thunder gun will explode, and Levi uses this to restrict Zeke's movement. There was no big problem with this approach, but Levi underestimated Zeke's consciousness. At the end of Chapter 114, Zeke detonated the thunder gun himself and chose to die with Levi.

The soldier commander had an extremely miserable life experience since he was a child. He has been living in an underground slum. Due to malnutrition, he missed the golden period of development, so that he will never grow as tall as he is now. Gao, until he met his uncle. In the author's opinion, it doesn't matter if the soldier commander is disfigured, it doesn't matter if he becomes a disabled person, and it doesn't matter if he needs to spend the rest of his life in a wheelchair. The only thing that matters is that the giant's power disappeared after Allen died, making the soldier's life a joke.