If anyone's wondering, I'm not reviewing the SWC entries based on their rankings --I have my own messed up priorities.
In any case, I have to say that I shouldn't be (considering your past exploits in the fiction arena), but I am, amazed at how you managed to write such a long story in the limited amount of time that we were allowed for the competition. It's a remarkable accomplishment for anyone and for that I commend you.
As for the piece itself, I can't really bring myself to do a complete breakdown because I want to do some other stuff tonight, but I can point out the bits that I liked, the bits that I really liked, the stuff that was amazing, and the stuff that made little sense, i.e the logical inconsistencies that I would find easy to chock up to a willing suspension of disbelief but won't because then I won't have much to say by way of critique. Anyway, I quite like stories that fill in the holes left by canon, especially the ones which weren't quite holes to begin with, and this was certainly no exception. The plot was amazingly well thought out because, usually, I'm not one for stories involving tribes and rituals, but this managed to stand out because of how you managed to make Sirinian's mind quite the modern one despite being raised among Neanderthals, a bit like an early Cro-Magnon. I guess it's because Sirinian didn't give off the kind of primal vibe that you usually associate with primeval stories like this. He was more the lost kid in the forest type who had a sense of sarcasm, something that I also love and find oddly out-of-place at the same time. Yeah, the slight sarcasm did add to his character, but, like Celebi, it felt slightly misplaced with the tone of the rest of the story. On that note, I did quite like Celebi and her references to the space-time continuum, even though it was awkward with everyone else being so serious.
Besides that, gotta love how you chose to depict Lorelei as the big-sister type, though I her willingness to tamper with time does bother me to an extent. I mean, it wasn't that hard to figure out that training hadn't been invented yet, since she was transported to when it began and all, so I was kind of hoping for her to be the silent observer type who would interact with the boy but would be unwilling to help him before realising that she was the one who started all of it. But no. Instead, she took an active role in shaping the course of human history without any deliberation for mucking up the timelines. Of course, this does say something for her strong-willed character, but it does indicate that she's a bit foolhardy with regards to her journeying. Otherwise, she knew that history worked as a closed time loop or Celebi pretty much hand waved the 'do not interfere' policy. In any case, her active interference pretty much cemented the foolhardy thing in my mind, but it didn't change the fact that I enjoyed how you showed her teaching Sirinian immensely.
Finally, I'm a bit iffy about the whole 'revenge' bit. It doesn't seem that satisfying to be honest, and I believe the interaction between Sirinian and the chief could've been handled a bit more tactfully, not like it was rushed. The whole encounter had the potential to be a bit more dramatic in my opinion.
Regardless, it was a splendid story and I loved it to bits. You've managed to combine quality with length and I'm disappointed that you didn't place higher despite the effort that must've gone into this. Amazing.