This story is good, but it's not because of the somewhat unique setting or that it started off as a tragedy.
It's just got characters that aren't bottom-tier cardboard cutouts, like you'd usually get in isekai.
I am worried that the illustrator will have trouble doing the novel justice later on. Right now it's fine, but when they'll have to depict entire civilizations or city-sized fortresses the quality will drop substantially. I guess we can enjoy it till then.