Demon Eyes Kyo is the most terrible samurai of the Tokugawa era, the slayer of over a thousand men... or rather he was. No one's seen him since the Battle of Sekigahara four years ago. He was having a macho staring contest with another samurai called Kyoshiro, but before they could start killing each other a meteor came screaming out of nowhere and turned the battlefield into ground zero. Tch. Couldn't it have waited? Still more tragically, even this didn't kill them, although it did lead to some fairly drastic lifestyle alterations. Kyoshiro has abandoned his former friends and is wandering the countryside as a medicine peddler, while Kyo is... well, that's where things get complicated.
In short, it's a load of rubbish. The best praise I can find is to call it in some ways competent, but the story it's chosen to tell is basically worthless. For the most part it's not bad, but boring.
The problem is the characters. The men are badass ninja or samurai without two interesting character traits to rub together. "I want to be the world's greatest swordsman!" "I want to rule Japan!" Oh, bugger off, the lot of you. Kyoshiro at first seems to be an exception and there was one (1) episode in which I was lulled into thinking he might become an interesting character, but no. In the end I managed to work up something that approximated to interest, but that's entirely due to the plot rather than the characters themselves. Basically they're a bunch of tossers who love fighting so much that they'd probably smack themselves in the head every night before going to bed if there wasn't anyone else about.
There's something interesting between Kyoshiro and Demon Eyes Kyo. That's pretty much a given, but unfortunately Kyo himself at the beginning is risible. The man's a twat. He's supposedly this terrifying embodiment of evil, whereas in fact he's a grinning poser. Not enough action, way too much "hey, I love myself so much that I'll stand here doing my best Joker impression and listen to the electric guitars on the soundtrack." Fortunately this only lasts a few episodes, since around episode four he goes into a strop that lasts the rest of the show. No grinning. You might think I'm making too much of the grinning, but you have no idea. Admittedly the result of all this is one more tedious macho idiot, but at least a stroppy Kyo doesn't make you want to put a boot through your television.
There are breasts, lurking somewhere behind which might perhaps be women. One of those, Yuya Shiina, could even be mistaken for having a character and I liked her. Firstly, she doesn't have stupid superpowers. Admittedly she has a gun, but in this show that's not much more effective than harsh language. Secondly, she's seeking revenge for her brother whom she suspects was killed by Demon Eyes Kyo. Yuya was the show's main character as far as I was concerned, having things like motivation and dramatic choices instead of just dick-waving contests... sorry, I mean swordfights. However I should get back to what the anime clearly thinks to be more important, i.e. the boobs. Obviously the 16th century was a time of heroic breast development in Japan, not to mention a cleavage-friendly style of kimono previously unknown to historians, yet the actual fanservice is useless. The show obviously has its mind set on the gutter, yet it doesn't even have the guts to get that far. The manga is apparently more graphic, both in blood and nudity.
The show's good bit is the ending, which is completely different from the manga's. Akimine Kamijyo was only halfway through the latter when the anime came out, so apparently the backstory and the origin of Demon Eyes Kyo is very different. I genuinely liked the anime's ending, which made me glad I'd watched the show and briefly even had me thinking well of it until I remembered all the other episodes.
Occasionally it makes a retarded attempt at comedy. There's also some ill-judged super-deformation. On both those points, the less said, the better.
There's a curious take on history, mixing famous real people and events (the Battle of Sekigahara, Yukimura Sanada) with famous literary heroes (Sasuke Sarutobi, a fictional ninja created in the Meiji era) and outright fantasy. The more you know about Japanese history, the more you'll get out of this show. I enjoyed seeing what they did with Tokugawa Ieyasu. However I couldn't recommend doing a college course on Japanese history and culture for the sake of watching an unmemorable anime, so anyone reading this review will have to accept that they weren't the target audience and as a result won't enjoy it as much as they would have if they were.
My opinion of this show fluctuated. Every ten episodes or so, it goes through phases of being quite good (circa episodes 5, 15, 25). However in between were endless wastes of boredom and annoyance, reminding me of Rurouni Kenshin in odd little ways that only underlined how infinitely superior that other show had been. There's a void at the heart of Samurai Deeper Kyo. The good guys are dreary and the bad guys are even worse. Almost all of the motivations are banal and/or stupidly macho. The superpowers are dumb, the fights are bad and the dialogue can be painful.
Occasionally the show raises its game to produce the odd interesting idea or scene, but basically it's dross. If you're going to judge on sheer badness then there's far worse out there, but I'd almost prefer that to this kind of mediocrity.