Okay.
It's no big secret at this point that I want the first enhancement and loathe the idea of the second. Since we're now on our way to finally go up to Byakuren and make our decision, now is the best time for me to at least try to explain where I'm coming from.
Why do I want the first enhancement? Because I want to remain human. I think retaining humanity makes for the better story. (Draco disagrees and I'm sure he'll be posting his stance at some point but for the purposes of this post that's neither here nor there.) Remember what Sanae said about her dream of flying a jet. Sure, Gensokyo natives can zip around in the air all the way without one, but she described the feeling of zipping around through the air, unsupported by magic, as romantic. This is exactly how I feel about the prospect of living in Gensokyo as a human as opposed to a youkai. It's like flying with the jet vs. flying with an ounce of willpower. I can try to elaborate further, but hopefully people will be able to see the comparison.
Why don't I want the second enhancement? Couple of reasons, most obvious at this point in this post being that, if I think remaining human makes for the better story, I must think going youkai makes for the worse one. It really feels soulless to go for youkai status. It's the easy way out to living in Gensokyo. We'll be just another face and name, whereas staying human is actually likely to garner us more notoriety while simultaneously allowing us to live the more peaceful life. Also, with humanity, we have a short amount of time with each other, and we'll be more inspired to make the most of it. Becoming a youkai seems like it would just result in a "okay, now what?" situation, which would be boring at best.
Second reason is that Renko's clearly uncomfortable on some level with the potential change the second enhancement brings about, as much as she tries to hide it. Remember that when it was initially brought up, she came up with the idea of trying to reverse the growth process, or simply going through with it as well if it was necessary. Upon being told that the growth is both uncontrollable and irreversable, her response is that "we could adapt if [Mari ends] up a bit bigger". There's obviously a problem going on there, simply because there would be no need to adapt to anything if there wasn't something forcing it to begin with. The response I'd expect from a Renko that really has no problems with it is something along the lines of "So what?" which "we could adapt" is very much not.
The last reason involves a bit of a set-up, as it's important to note a few things.
- Maribel has gone the entire game so far looking to help people and avoid fights as much as possible. Her current clearest career path is the teaching gig, and given the subject matter, there wouldn't be a whole lot of magic required.
- Renko is now on record as not really being concerned with boosting herself. Clearly she thinks she could live out her life and be happy without any enhancement at all, and that may very well be true, given her career plans also don't seem to involve direct combat outside of the SDM fight.
- Byakuren warned us of the karmic penalty willingly changing from human to youkai would incur. We have conflicting reports on the severity of this, yes, but the person that has gone through it herself and would be administering it to us is the one telling us that we'll be eating it for a long time. (I think it is safe to assume that, if the change is gradual and inevitable, the karmic hit would be a lot less, or possibly not happen at all.)
- In talking to Purvis about this whole situation, he told me that we could have actually completed this quest without learning a single drop of magic. It is, has been and will be very helpful, but it was never required. One of the things Draco asked me in private was whether or not I believed we could take Alice without the second enhancement: suffice to say that I would not be arguing this position if I didn't think it possible to confront Alice with just the first enhancement. And I had been thinking this long before I talked to Purvis.
Sum up all those parts, and what do we get? An inability to find a good in-character reason to take the second enhancement, and the cold reality that we would only be doing it as a powergrab. Why do we need this? We don't need it to love Renko, we don't need it to explore, we don't need it to teach, and we don't need it to beat Alice. Grabbing for power would go against pretty much everything our Maribel has done so far and provide benefits only in the areas she hasn't been concerned with. However much stock you put into Byakuren's karma warnings regarding this enhancement, there is no way in hell powergrabbing is going to help our karmic situation at all, and it is, in fact, quite likely to make it a lot worse.