avbutt

I think I meant “forgone” here

She is among the first people he's met in the world. Even if it's for a short time, a bond would have been formed, so it's hard to simply abandon them.

Well, "he" didn't even kill her brother. It was completely out of his control. And, one of them had to die anyway; it was either him or her brother.

he is, partially

I see what you mean; I'm sorry if I made it unclear. I meant to say that by raising his hand over his head, his elbow is protecting his nose, jaw, and mouth

Read the previous sentence, "Seeing he had the high ground," the hero is elevated above him. I went over and visualized this fight multiple times; it works, as far as I know.

He's not totally basing his actions on this hypothesis. One concrete thing that he knows is the time of his death in ten years, as it is written in the book. So, he wants to go to the academy to try and prevent that.

yeah, that's true, he's just theorizing. More of how he was transmigrated will be revealed

...? Heavier things fall faster in the air. he is heavier than the two swords, so he falls faster ​

Good point, I'll add that in