Like Naruto himself who is always aspiring to become the Hokage of his village, the hero of this manga, Jio Freed, has a dream himself, just a bit more ambitious; to rule the world. He is joined by a handful of friends as they embark on a journey to fulfill each of their dreams; but like every shounen story, little do they know they're in for another save the world plot. As generic and vague a description that is, it's actually a pretty fun ride. Although the concepts of the O-Parts, specialized weapons each with different and unique attributes to use during battle, are nothing special, the fights themselves are well choreographed and are exciting to watch. Each of the fights are constructed using intense strategies and tactics that almost always have you on the edge of your seat.
It is pretty clear that Seishi Kishimoto devoted quite some time creating the battles, but he also made sure that the story was just as great. Although not to spoil the goods, it's a bit like Naruto's tailed beasts concept, except replace the monsters with demons and angels. Like Naruto who is harboring one of these monsters within him, Jio Freed is also the same who actually carries within him Satan, the strongest of them all. Over the course of the story, we are told bits by bits the mysteries of the these demons and angels, along with the origins of O-Parts and the history of the world. The pacing is one of the best you'll find in a shounen and the execution is just perfect.
Although it may seem like Jio Freed is just a Naruto copy cat, the characters as a whole, including Jio, are just much more likable and believable than the ones in Naruto. They're more developed, they have better chemistry with each other, and just show more emotion. Kirin, this manga's version of Kakashi, just seems to have a more interesting personality, and Ball, who is actually the playful rival of Jio, is actually the better bestfriend compliment as oppose to Sasuke. For a while, 666 Satan was actually molding to be the better version of Naruto.
That is until it hits a certain plot twist, which I should add was absolutely great, but it dives head first into the dumps afterwards. When a manga was being paced so nicely for 50 chapters and offers nothing but quality after quality chapters, and then wraps it up suddenly in just a matter of 26 chapters, it's just unbelievable how one of the better shounen mangas out there is just absolutely ruined. The battles remain somewhat consistent, but the character development and the story just turn into complete shambles. And the sad part is that it wasn't just a matter of declining quality; you could see how the manga would be like if it were stretched out into at least 50 more chapters, but it's as if the editor told Seishi Kishimoto to wrap it up, took out all sense of quality in the remaining plot, and called it a day.
Really a shame. A huge huge shame. It was firing on all cylinders and doing everything great that a manga should be doing. A phenomenally memorable cast, some eye pleasing battles, a nicely paced storyline coupled with some stunning plot twists, but the last 1/3rd of the manga was just bad. Almost bad enough to drag the other 2/3rds into complete mediocrity, but fortunately it wasn't THAT bad. 666 Satan is largely still one of the better shounen reads out there and is a must read for fans of the genre, especially Naruto fans, but expect to be disappointed towards the end, big time.
