The Basement isn't a place for small children, and Isaac knew this well. As he stumbled through countless doorways and dead ends, his mind raced with thoughts that dealt with the supposedly forgiving God and his own mortality. For a while he had forgot his own age; only after seeing a ripped of picture of him and his mother lead to the restoration of that memory. Five. He's five.
Well, five is an awfully young age to die. He can't say he's interested in dying. Though, he's beginning to swallow the fact he might die, because he only has a half a heart left and the shop had a Greed inside it instead of something beneficial to his survival. And in all fairness, he's scared. Fear leads to panicking. Panicking leads to reckless choices. Reckless choices leads to him being buried six feat under.
That's why when you showed up, and he was certain you would be the last thing he'd ever see. You were too strong, too fast, too tall, too everything that's anti-survival. Only after internalizing the fact this battle is not gonna end in his favor, he gave up. It was hardly an easy option; he had fat wet tears rolling down his chubby cheeks and was shaking more than a stray leaf holding onto a branch and all he wanted to do was get out of here alive somehow.
Isaac was so distraught over his immanent death in fact, that he failed to notice that you stopped attacking and are now staring at him with what one can only assume as curiosity.