[Spoilers for ZnT Season 1]
First, the basics: if you've seen the first Zero no Tsukaima series (as you should, if you're watching Futatsuki no Kishi), you know what to expect for both animation and sound. The animation is cute and pretty fluid without being too detailed - pretty easy on the eyes. I saw not a single difference from Season 1, and that's hardly a bad thing. Same goes for the sound, as many of the background tracks were pulled directly from the original. I don't aim to knock it for that, though - the tracks were very fitting, and gave many scenes some very welcome extra emotional weight. I highly enjoyed the new OP; it was nothing special, but fit the tone well, and was catchy without being overly saccharine. Superior to the original OP. On the other hand, the ED...oh, what were you thinking, J.C. Staff?! Don't get me wrong, I loved the Season 1 ED, in all it's mildly obnoxious glory. This one, at least to me, was beyond redemption, especially when it absolutely shattered the powerful mood created in some of the later episodes (a lá Clannad After Story). Voice acting continues to be great: I can do nothing but love Kugimiya Rei's tsundere growls. With that out of the way, onto the meat of this review: Story and Characters.
[Before I start, keep in mind this is my first review. I usually don't write them because I feel that my thoughts about a series after I finish tend to be along the lines of "GWAHAHAHA SO GOOOOOD-", and the world doesn't need to hear my fanboy ranting. In this case, though, having finished Futatsuki no Kishi minutes ago, we're gonna try this. Here goes.]
I absolutely adored the first Zero no Tsukaima series, and not in cynical sense, either. It was simple and predictable (even for someone like myself who finds himself surprised at the most simple of plots), but it had an undeniable charm to it that drew me in episode after episode. The one aspect that stuck out to me most was Saito himself - a male lead in a romantic comedy who really earns his admiration, and doesn't just awkwardly have it thrust upon him. He was a relentlessly fun character to watch and relate to as he struggled to find his place in the world entrenched in old customs that he's been thrown into.
So, Futatsuki no Kishi started on a rather bad note for me.
To be frank, Saito is a different person in this series. His personality seems almost fragmented, as if a wily and horribly perverted demon has invaded his mind, and takes control every so often. We still see glimpses of the boy that stood up to snobby aristocrats simply because you don't f-ck with Saito, but just as often, we have to painfully watch him drool over every remotely pretty girl he sees, implying that much of the relationship we saw develop with Louise has been lost in translation. Thankfully, this becomes less noticable as the series progresses.
Disregarding Saito's ogling tendencies, the story here is pretty fantastic. It's still ZnT, so you'll be getting romantic comedy with some action thrown in for good measure - however, I was pleasantly surprised by the amount of genuine emotion created in a great deal of the 12 episodes. Episode 9, in particular, is magnificent - I would go so far as to call a masterpiece within a work of lesser overall quality. If you have any doubts about this series, I recommend that you watch it for that very reason. I am equal parts ashamed and myself and proud of the series to be able to say that Zero no Tsukaima: Futatsuki no Kishi brought more than a few glorious, manly tears to my eyes. It's still a predictable tale, but much less so than the original, and it certainly goes to darker territory, and for that, I applaud the writers. However, Futatsuki no Kishi reminded me once again that it's very hard to do an ending right all the way through. The majority of the final episode is remarkably good, and definitely the high point of the series aside from the previously mentioned ep 9. At the same time, while I don't want to spoil anything, I will say that if deus ex machina isn't your thing, you will be disappointed. To top it off, the overarching plot has no conclusion to speak of (lucky us, though, there is yet another sequel out with now another currently airing, so this complaint carries less weight in 2012!)
The characters themselves are a mixed bag. You already know how I feel about Saito: he suffers when compared to the first series, but still has his share of great moments. Fellow students Kirche, Montmorency, Tabitha and Guiche have faded (even further?) into the background. Poor Tabitha, I think I could count on one hand how many words she said in the whole series...okay, maybe two hands. However, Princess Henrietta comes into her own as a character, as well as another familiar face from the original who turns out a surprising and stunningly powerful performance. New-comers Agnes and Julio both prove entertaining and endearing, especially the former, who impressed me quite a bit, after giving a poor first impression in early episodes.
Overall, Zero no Tsukaima: Futatsuki no Kishi is an incredibly imperfect series that could have been truly wonderful, given a few changes. Regardless, if you enjoyed the first series, you will find plenty to love here - the difference is that while the original maintained a consistent level of "pleasant and endearing", the sequel bounces between awesome and unfortunate. Indeed, the story has moments of true greatness, but the moral here is this, J.C. Staff: NEVER change the personality of a great character for the sole purpose of adding fan-service. It's doing more harm than good.
[Well, I hope that wasn't too painful, being a first review and all. Hopefully it was informative, and maybe even entertaining! Cheers - Squatso]