Saint Seiya Hades Sanctuary was both an extremely well done production & a giant blast of nostalgia for the pre-existing fanbase. The success of the OVA series lead to Toei making a new Seiya movie, the first in 15 years, that would finally continue off of the manga's ending. The final product, 2004's Tenkai-hen Jousou ~Overture~, was a fine movie in itself but director Shigeyasu Yamauchi may have overstepped his boundaries in focusing on making the movie he wanted instead of telling the story Masami Kurumada wrote. Kurumada was so displeased with the amount of changes the movie made from his planned story that he removed Yamauchi from all future Seiya Hades OVAs. Combined with the recasting of the five main characters, this resulted in (supposedly) massive hatred from the Seiya fans. The Hades Chapter anime adaptation would return to Animax in late 2005 with Saint Seiya Hades Inferno, a production that was noticeably different from the previous. Not just from a staff & main cast side of things, mind you, but also from a release perspective: All 12 episodes were split up into two parts, literally called Zenshou & Koushou/Former Part & Latter Part, with the first part debuting from December 2005 to February 2006 & the second part from the same months in 2006-2007. The obvious reason for the split was because Toei was alternating between doing a Ring ni Kakero 1 anime season & then a Seiya Hades production, but all of this added up to the hardcore fanbase absolutely hating this second part of the Hades Chapter OVAs. But, honestly, was all of the hate warranted?
The Inferno: The domain of Hades, God of the Underworld. In order to put an end to the newly started Holy War that began with the invasion of Sanctuary, Athena has decided to go to Hades' territory while still alive by relying on the Arayashiki, the "Eight Sense" of Buddhism. Meanwhile, Seiya & his friends also make their way into the Inferno to deliver Athena her Cloth, because otherwise she won't be able to fight Hades if need be. Alongside Gemini Kanon & later Phoenix Ikki, Seiya and the others have to make it past the eight prisons of the Inferno, each guarded by numerous Specters, in order to reach Judecca, the final palace in Cocytus where Hades sits atop his throne.
[NOTE: I'll try to keep spoilers to the middle of a story arc to a minimum, but advance at your own risk.]
If Hades Sanctuary was a bit of a change up from the usual Seiya story arc model, then Hades Inferno is a return to form, at least in the beginning. The first episode has Seiya & Shun cross the River Acheron with Acheron Charon, the Specter who brings the dead from the Gate of Hell ("Abandon All Hope, Ye Who Enter Here") to the Inferno itself, with Charon bringing up how there are eight prisons, three valleys, and so on that have to passed in order to reach Judecca. So the model stays intact as Seiya & Shun take on Balrog René at the Silent Court (the first prison), and then it starts to change. At the second prison they try to take on Sphinx Pharaoh but are interrupted by Lyra Orpheé (Orpheus in some translations), a Silver Saint of Gold Saint-level strength who came to the Inferno a few years back in an attempt to bring back from death Eurydice, the woman he loved. The Pharaoh/Orpheé story is actually really neat & follows the legend of Orpheus really nicely while also giving a type of closure to the idea behind it. After this point, though, the traditional Seiya model of fighting an enemy at each new section is mostly tossed aside for some real storytelling.
Just to point out, the model isn't abandoned outright, but rather it's played with by Hyoga, Shiryu, & Kanon. While Seiya & Shun get a shortcut to Judecca, the others advance on to each prison in order, defeating Specters with little to no trouble. The third prison's Specter, Golem Rock, is defeated in one blow & the Troll Specter is destroyed before even saying his name! This continues into the fifth prison, where the three are stopped by the Three Judges of Hell, Wyvern Rhadamanthys, Garuda Aiakos, & Griffon Minos, who are some of the strongest of the 108 Specters. This is where Kanon's story becomes solidified as he tells Hyoga & Shiryu to advance on, & this is also where Ikki literally just emerges into the story. At this point Hades Inferno has three main storylines going on: Seiya & Shun (and later Ikki) at Judecca, Kanon at the fifth prison with the Judges, & Hyoga and Shiryu running roughshod through the prisons.
Of the three storylines, the main focus is on the happenings in Judecca & the frozen graveyard of Cocytus. In a nice method of operation, though, a lot happens in that one area. There's Seiya & Shun's initial attempt at defeating Hades, Ikki being teleported there to see Hades himself, Seiya being thrown into Cocytus to die & later fighting Harpy Valentine, and then Athena & Shaka finally making it to Hades himself. To this OVA series' credit, there's actually a good amount of content to every episode; it really feels like each episode is longer than the ~24 minutes they actually are. There's never a moment where everything just stops dead & becomes boring, and the major fights are generally really cool to watch as well. As always, even though Kurumada's villains don't get much in terms of development, they do ooze a great sense of memorability. No matter how much time passes I have never forgotten the names & actions behind Charon, René, Pharaoh, & Valentine, and the Judges themselves have always given off a great sense of immense power & ability. Combine that with Kurumada's generally excellent naming sense when it comes to attacks, resulting in names like Greed of Life, Galactica Illusion, & Greatest Caution, and it's easy to see why the Hades Chapter as a whole is so well loved & not just simply the Sanctuary portion.
That being said, it is tough tell whether Kurumada originally wanted to have this portion of the story arc be longer & had to shorten it due to his editors or if he always had this pacing in mind. If one couldn't tell already, this part of the story is heavily influenced by Dante Alighieri's epic poem The Divine Comedy, and there are a whole lot more references to Greek mythology. The prisons were obviously based on the nine circles of Hell that Dante wrote about, complete with Charon bringing up the ten Bolgias within the prison of Malebolge (Dante's eighth circle of Hell), and I'm sure Kurumada would have loved to showcase his take on these ideas in more detail; instead, only the first five prisons & Cocytus are given any description. Shiryu & Hyoga literally running through each prison, killing Specters like they were measely flies, feels both like Kurumada being forced to rush through the story & also the man himself poking fun at the model that he helped create (& is still used to this very day). There's also slightly heavy use of the phrase, "The Same Technique Won't Work Twice on a Saint," especially from Kanon & Ikki, which both assures how confident the heroes are of their strength & almost comes off as an inside joke from Kurumada. At the same time, though, the main story in Judecca that is told is definitely one that felt planned out & not rushed much, if at all. It's odd how the story that Hades Inferno tells comes off as both rushed & planned out with good pacing, depending on which part of the story you look at.
As mentioned in the beginning, though, no amount of solid storytelling, great pacing, & memorable characters was going to make the hardest of the hardcore like this production that removed some of their strongest nostalgia. Toei, in turn, seemed to not care as much about this production as they did with Hades Sanctuary; if the fans were going to hate, then why should Toei break the bank? Still, it's not like the overall production side of things wasn't impressive. Replacing Shigeyasu Yamauchi was Tomoharu Katsumata, a man who's been with Toei for decades & directed some of their iconic 70s series such as UFO Robo Grendizer, Wakusei Robo Danguard Ace, Daiku Maryu Gaiking, & the original Cutie Honey and Devilman productions. Katsumata was in no way an inexperienced director, and he had done storyboards & direction on a few episodes of the original Seiya anime, so Hades Inferno still looks & operates admirably. The main change is that there are very notable moments of the lower animation budget, like maybe a slightly wonky-looking drawing or reusing (or even simply rewinding) a shot for a later moment. If anything, this production just feels more "traditional" than anything. It doesn't look bad by any means, there are numerous shots that still look great, but it is an obvious difference when comparing to the OVA series that came before it. This is a perfect case of how complaining & whining results in completely realistic results instead of the warped, "They'll bend to our complaints!" logic some fans have. Yes, bringing up problems & showcasing disapproval is fine, but sometimes fans do react in a way that doesn't sound reasonable.
Returning back to the staff, series composer Michiko Yokote was replaced by Yousuke Kuroda, who had the same role for the Ring ni Kakero 1 anime, and he partially represents another "complaint" that the hardcore fans had: There was seemingly too much carry-over from RnK1. Yes, Kuroda (& some seiyuu) did seem to crossover to Seiya from RnK1, but I think this was nothing more than fans grasping at straws because they couldn't find anything else to whine about. Kuroda, much like Yokote, stayed true to the original manga as much as possible, altering very little in the process. In fact, the only real notable change was in the last couple of episodes, where the Gold Saints unite in an attempt to destroy the Wailing Wall (also known as the Wall of Lamentation or Grief, depending on the product), which separates the Inferno from Elysium, a.k.a. the "Utopia" of the Gods. In the manga Hyoga & Shiryu weren't around to see it happen, but the anime has them arrive in time & allows the story to stretch out a little. Really, the last three episodes do honestly drag slightly, but that was obviously done so that this series could end at a very specific point, so it's somewhat forgivable. Otherwise, Kuroda did a perfectly fine job. Shingo Araki, Michi Himeno, & Seiji Yokoyama all return to their respective positions and do their usual quality. The opening theme here is "Megami no Senshi ~Pegasus Forever~" by Marina del ray, a heart-pounding & excellent modern-day counterpart to "Pegasus Fantasy"; even the vehement haters have warmed up to the song. The ending theme is "Takusu mono he ~My dear~" by Yumi Matsuzawa, which is another beautiful slow song from a woman with an absolutely talented singing ability; if sounds were visible I'm sure Matsuzawa's could be called gorgeous. Like all anime based directly on Masami Kurumada's work in the past decade, these songs were both co-written by the man himself with help from Koji Matsuo, helping to lend a sort of official status to them as absolute themes to Saint Seiya.
Then there's the new cast for the main characters, who obviously had big shoes to fill but do a fine job once you finally accept the fact that they aren't the original cast. The one who easily got the most hatred was the new voice of Seiya, Masakazu Morita (Ichigo in Bleach, Ryuji Takane in Ring ni Kakero 1). Originally a motion capture actor who was the "movement" behind Zell Dincht in Final Fantasy VIII, Morita got into voice acting while doing the motion capture for Tidus in 2001's Final Fantasy X; since there was no chosen voice for the lead, Morita auditioned & got the role. It wasn't until 2004, though, that Morita really burst onto the scene, getting a long-lasting role (seven years) with Ichigo & a (eventually) re-occurring role as Ryuji. Many fans hated the idea that a relative newbie was being given one of Tohru Furuya's iconic roles, Morita didn't exactly get a strong fanbase until later, and some probably thought that Morita was only given the role of Seiya because he voiced Ryuji. Honestly, regardless of the "why", Morita delivers a good performance & it's obvious that he treated the role with respect. Whether it's Seiya being sarcastic, sad, angry, or hot-blooded, Morita does a good job & only improves as time goes on; his performance in the Brave Soldiers fighting game really shows off how he's improved greatly with time. Yes, it isn't the same kind of performance as what Tohru Furuya always delivered with Seiya, but I do think Masakazu Morita has always tended to get a little too much flak from the hardcore Seiya fans.
As for the other new seiyuu, the second most prominent in this OVA series is Yuta Kazuya, who voices Shun (the only real notable role in his career). Kazuya definitely tries harnessing Ryo Horikawa by giving Shun a heavily feminine-sounding voice, but it can be argued that he may have overdone it early on. Granted, it does work for the character & when a somewhat deeper voice is need Kazuya does well, but after hearing Horikawa's aged performance in Hades Sanctuary it is a little too much of a shift in pitch; Kazuya does really improve as time goes on, though. Hyoga & Shiryu are voiced by Hiroaki Miura (Gan Ning in the Warriors/Musou video game series) & Takahiro Sakurai (Suzaku in Code Geass, Shadow Sousui in Ring ni Kakero 1), respectively, and showcase a mix of homaging their predecessors while putting some of themselves into their characters. In other words, Miura gives his attack name shouting a similar style as that of Kouichi Hashimoto, while Sakurai gruff his voice like Hirotaka Suzuoki when needed; in recent video games Sakurai even gives Shiryu some Bruce Lee-esque kiai. Ikki is handled by Katsuyuki Konishi (Kamina in Gurren Lagann, Oga in Beelzebub), who homages his predecessor the most by giving a very Hideyuki Hori-esque performance, right down to having a nearly pitch perfect Hori-style scream of pain. Finally, I neglected to mention Athena in the previous OVA series, who was reprised by Keiko Han, but here she is recast with Fumiko Orikasa (Rukia in Bleach, the present voice of Street Fighter's Chuin-Li), who does a really good job here, giving Athena a nice feeling of godliness.
To round everything out, let's go over the characters that Hades Inferno focuses on. Rhadamanthys is voiced by the venerable Takehito Koyasu, who delivers an enjoyably evil & cocky performance; he sometimes holds onto the "n" in Greatest Caution with surprising awesomeness. In comparison, Maaya Sakamoto's Pandora is similar to Orikasa's performance in that it has a sense of regality, but Pandora does have her moments of anger & worry, which Sakamoto also delivers very well. Orpheé is performed by Hiroshi Kamiya, who utilizes his usual calm, cool demeanor while also being able to do more excited moments really well. Finally, performances by Junichi Suwabe (Pharaoh), Kouichi Toochika (Minos), Shinichiro Miki (Aiakos), & Eiji Takemoto (Valentine) are very well done, among others. To the complainers' credit, there is admittedly a fair share of overlap with Ring ni Kakero 1, each member of Golden Japan Jr. also voices a Saint & a number of seiyuu do minor roles for both series, but I chalk that up more as sheer coincidence than anything substantial. Also, both series relied heavily on talent agency Aoni Production for their casts, so overlap is understandable.
Saint Seiya Hades Inferno had the unenviable position of being made after a very well done predecessor was produced, but two of the things that fans loved about it the most (Yamauchi & the original cast) were removed in the time between productions. The super hardcore instantly hated it because their nostalgia wasn't being fed to them, so Toei obviously didn't care as much about the idea of adapting the Hades Chapter at this point; the animation budget shows this. Let's not forget, though, that the super hardcore tend to only make up a small portion of the overall fanbase, vocal minority & all, with the Seiya fandom at large generally liking this production. Personally, I agree with the fandom at large here, because while the lower budget does rear its head at times the story, characters, & pacing are just way too good to end up hating the final product. Much like Hades Sanctuary, Inferno adapted another four volumes (well, 3.75 volumes if you wanna be technical) of the manga, leaving only volumes 27 & 28 to be adapted. This last part of the original Saint Seiya story would finally come to anime the following year... But would the truly hardcore give a damn by then?