This was really good! Honestly better than I was expecting going into it (the store page could use a bit of love).
Working through each criterion, spoilers from this point forward.
Implementation of Theme:
I think there's a couple different ways to look at this here. In one sense, we have the darkness of the famine itself, from which Angus' actions provide a light for the people, causing the town to boom and all of its residents to, y'know, not die and all. I think what you were primarily going for though was Faolan's inner turmoil of both losing Iomhar and his subsequent inability to keep the world from falling to shit as his "darkness", and the reemergence of Iomhar reincarnated (?) in Angus to be the "light" to pull him out of that spiral. There were long stretches early on in the VN where I wasn't sure where exactly we were going with this, but I think it works well enough.
Story:
Really well-done for the most part (with a couple things to flag that I'll get to in a second). Both of our main characters felt like actual people rather than one-note caricatures, and even Desmond came across as well-written in all of his scenes despite being much more of a secondary participant. I think this VN particularly excelled in humanizing Faolan through the shifts from his confidence and superiority upon first introduction to him dodging emotional confrontation just like a normal person who's in over their head later.
I'm not sure the romance itself particularly works for me up until the Iomhar reveal though. This twist does soften some of the previous interactions, but it felt very Stockholm Syndrome-y to have Angus fall in love with Faolan while Faolan was essentially holding his soul hostage to save the rest of the town. Desmond's objection contributes to this as well - Faolan was destroying Angus, and I'm not sure Angus really fully contemplated the full scope of how manipulative their relationship came off. Seems like others didn't have as much of a problem here though, so maybe just me.
I'm also a bit confused on what exactly the relationship between Iomhar and Angus is in the story. Like, yes, they are different and also the same, but is the idea that Angus was actually like a full-on reincarnation of Iomhar? Or was Iomhar's soul like, grafted onto Angus when he "died"? Or did Angus just become a representation of Iomhar once he made his decision to be nice to the locust? The answer here kind of colors what could be going on in Angus' subconscious during his interactions with Faolan, so maybe that could use some clarification.
Sex scene felt a little gratuitous but it didn't overstay its welcome long enough for it to really be a big deal.
Presentation:
Far and away the best use of the stock sprites I've seen so far in the jam. There was some occasional background music here as well which helped set the tone while being quiet and unintrusive (that may not sound like high praise, but I really did think it was a positive). The little CG progression of Faolan looking up into the night sky as Iomhar faded away was a great example of having extremely simple imagery being very effective, and it was nice to see the extra effort.
Creativity:
I'm probably not quite through half the jam entries at this point, but I highly doubt there will be another instance of male red wine lactation. So there's that. Otherwise, as mentioned, great use of the stock sprites to build a character that was very on theme, and also just a solid effort all around to create a supernatural romance that didn't devolve into tired cliches and tropes. This was very solid.