This is probably a horrible head cannon but when coined zack from a background character I kinda had this idea that he was In love with Jonathan. And as Jonathan becomes more and more shut out because of him seeming too loose his mind Zack confronts him with consirns, A bit too forward for Socks liking. Not that Sock was really angry at zack just confused and protective.
Basicly the head cannon is that sock will posess Jonathan to kill zack, but zack just thinks that jonathan is so far gone because he starts speaking to himself in the third person, and insted of using his strenght to defend and save himself, he lets himself be killed. Because he knows he would have to hurt Jonathan in order to save himself and he couldn’t bare that thought.