Alex kept on attacking Lilitth, and every time he hit her he noticed that he was doing some damage to her body, but her wounds looked like they were instantly healing. It was not too fast that you can really call it instant, but it was fast enough for the naked eye to see the wounds healing.
Alex simply wanted to end this quickly. He didn't like the feeling of hurting this little girl even further. Yet every time he gets a decisive hit, the damage dealt wasn't deep enough to stop her, she simply kept on coming. So the more time passed the more Alex had difficulty attacking Lilitth. If he could, he just wanted to escape from this room, with Alisa and Evangeline in tow.
Yet to open the iron door, will take some time, and he was sure that this girl called Lilitth wouldn't give him the time he needed. Alex shook his head trying to focus on the battle at hand.
'Tsk, so many idle thoughts as I fight... Seriously what is happening to me?...'
Onii-san means older brother in Japanese. The reason I wrote it that way even before, because it sounded right based on the Lilitth's character.