I'll be perfectly honest... having finished Shizuma's path, the only thing I can say is that he was a total douche-bag intelligent self-hating moron to the end.   Being inside his mind was depressing, right from the beginning to the end. While I loved most of the other characters on his path, I hated him and his heroines, also from beginning to end.  Similar to Kai, he is actually more effective on foot than he is riding in Stigma.  Stigma is slightly more durable than Alfaria, and she definitely has a lot better support skills.  However, when it came down to it, all that meant was that I had to keep a piece of deadweight alive through the entire game.  Gameplay-wise, that is a nightmare in both Kai's and Shizuma's paths. 

I did like the characters in Shizuma's path more than the ones in Kai's, because they seemed more human (except the psychopath).  Unfortunately, there really was no reason why they should have stuck with Shizuma.  He resents them through most of the game, takes out his frustrations on them frequently, and generally makes an ass of himself.  Also, there was a huge load of 'what was the point of all that?' self-pity from Shizuma for about the last half of his path that made me feel like I wanted to smash his head in.

Shizuma's story is dark... but it isn't the kind of darkness you can sit back and take pleasure in.  It is the kind of darkness that gives you a headache because it is largely born out of Shizuma's idiocy after a certain point of the game.  Yes, I unreservedly hate Shizuma.  I don't mind characters that get twisted by the things they have to do, but self-hating, self-pitying idiots with 18 Intelligence and 0 Wisdom make me want to smash things.  He does not evolve or really learn from his mistakes, and his paranoia gets old, fast.

Story-wise... there are way too many inconsistencies between the two paths, even where they meet.  I had to honestly throw my hands up in frustration at trying to figure out how they meant the game to make sense.  Not only that, but throughout Shizuma's path you see bits of the backstage that should have really come to the forefront at some point but fizzle out, with the inability to access the third path making me want to do the 'crazy dance'.  There should be a third path, because none of the crap that happens in this game is conclusive in any way.  They hinted at a third path before release.  So why can't I access it after completing both paths once, I wonder?  If they mean to release it as a sequel, I'm just going to forget about this game entirely.

I am also at least partially sure that heroine choice actually effects things more than it really should in this type of game, due to the sheer amount of extra battles I had to fight in comparison to Kai's path.  Since Veridadear is a really easy to notice secondary heroine, I suppose going down her path probably creates a much different outcome from choosing Alfaria.  Choosing Stigma in Shizuma's path resulted in a nightmare rollercoaster of endless death that made me bored halfway through (I know that sounds impossible - me loving endless death -, but the way the story for Shizuma's path stumbled so completely after the turning point made me want to scream).

Update

Ok, the thing you have to do to access the third path is to complete Stigma's and Alfaria's path, as I suspected *sighs*.  The difference in length and difficulty between Alfaria's path and Veridadear's path is pretty extreme... and at the end, after playing through the equivalent of two full VN-rpgs?  You have to play yet another path... the best thing I can say about it is that you actually find out what was going on behind the scenes to some extent early on.  I'm really tired of this game... for obvious reasons.  Nonetheless, I'll keep playing this until it is over, lol.