
Abel doesn't want him to kill the hostage that the man is holding on to. Karas is willing to kill the hostage without issue just because they are in the way and that's who Abel is comparing to an innocent bug.
Abel sees he doesn't care about the hostages getting killed once the first one gets hurt and is stopping him before he ends up killing the second hostage.
In the novel, Karas kills MULTIPLE hostages that aren't even being used as shields to prove a point, including the first one who is only hurt in this version.
They extremely toned down what he does he this chapter.
I do like that Abel acted much quicker to stop him in this though.

Sorry my bad, slight correction. In the novel Karas doesn't kill the first hostage the fake is holding onto....he just turns away goes straight to the other people and kills them one by one using them as his own hostages.
He tells the fake to kill the hostage he has or "otherwise these people will die because of you." And then Abel stops him from killing all of the innocent people on board, comparing them to the bug, and explaining how they did nothing wrong.
He spared a rapist (yknow he was with how he acted drunk that’s he’s assaulted a few women) and an attempted murderer, if he wasn’t already… Ik y’all in the cmts justifying Abel’s decision bc of his background, but DAMN does it leave a bad taste in my mouth to see a holy moly character. Hope Kara’s deals with him in secret.