"(Twink) Death (of) the Thief of Stars"! In all seriousness though, I've never had any contact with this side of folklore or mythology, but even if this were a 1:1 retelling of a myth, the execution is so skillful that I would find it hard to use that against it.
The art is sublime, the writing flows, and the story is very captivating, so I find it hard to pick out many weaknesses in this submission. Only a couple of small things irked me a little during the whole game, and for a project this long, for so few slips to occur is also worth commending.
The only real issue worth mentioning is that by the end of the story, I had grown quite tired of Libulan's whole "No one understands me" shtick while refusing to elaborate much beyond "My brother was always more important," while at the same time seemingly refusing to talk with anyone other than the protagonist. Now, it may be that he tried and failed, or perhaps his brother lies about it, but if that's the case, he doesn't disclose any of it either.
Nevertheless, this detracts very, very little from the project, and I still found myself heavily invested in the characters and the story for its entire duration.