After a while, Ethan confirmed what he had thought early. Those memories were of his first battle, his first battle where he had been the sole survivor. Even though Ethan at that time wasn't that experience and had yet to develop his iron will, he fought and continued to fight while chasing the gremlins for numerous hours. Until it reached a moment where he couldn't see anyone following him by behind.
Ethan blamed himself for being so pathetic that he couldn't even protect those who decided to fight alongside him. What a pathetic excuse of a hero… Still, he quickly came to the terms with those deaths. He didn't have time to mourn them and he, and he had to exterminate all of the gremlins. That had been his mission since the very moment.