So what is so special about that girly looking Sephiroth anyway?
This is a rhetorical question that I'm actually going to answer in this post, as the original quality of the character has been lost over the years (thanks to fandom and Square itself).
Firstly, what is the image of the character now? Sephiroth's image has been shaped into what I call "the fangirl Sephiroth." To be more specific, his character is now all about his design and not about his actual character anymore. Yes, he looks cool. Yes, he's designed to be attractive to females. No, that's not at all why he is one of the greatest villains in any videya game. Square has even molded his current self around this fangirl image in its recent Compilation of Final Fantasy VII (which itself has all but murdered the greatness of the original game).
So what made Sephiroth so great to begin with? For one, when the game first came out there was almost NO mention of Sephiroth in its marketing. The story was summed up as Cloud and co. versus the Shinra Corporation. I'd been following that game's marketing for two years prior to its release, and the first time I ever heard the name "Sephiroth" was in the game, where he was referred to only in passing.
In fact, throughout the enitre first act of the game -- Midgar -- Sephiroth is barely mentioned, never shown, and only talked about in passing. The character's reveal is as big of a twist as Aeris' death was, and this is completely lost on people who play the game for the first time now.
Secondly, he is an extremely well-written and in-depth character, whose personality changes and develops. Also, his parents and their stories are established. Early on in the game you almost feel sorry for him, until you realize he has gone way over the edge and become a purely villainous character.
Sephiroth is compared frequently to Kefka in a "North Vs. South" war of fans of which villain is the best. This is entirely unfair and based only on opinion as these two characters are completely different. Kefka is also one of the best characters Square has ever developed and one of the greatest villains. What he is NOT, though, is a character with a lot of depth. People mistake depth for quality sometimes, when a character can sometimes benefit from lack of depth. The best, and most comparable example of this is Heath Ledger's Joker from The Dark Knight. When Chris Nolan wrote the character of the Joker, he purposely did not give him a backstory or origin. He did not want the character to be anything more than a full force of evil, and that's what Kefka is. On the other hand, Sephiroth is a character who benefits from what you learn of him as the game progresses.
Finally, and this is -- in my opinion -- the single greatest reason of why Sephiroth's character was so successful, and also the one that Square has mostly lost sight of in their Compilation. Kefka's theme is crazy, while Sephiroth's theme is fear. Even their theme songs give off that feeling, and when I say Sephiroth's theme song, I mean "Those Chosen By the Planet" and NOT the final battle tune.
Square wrote Sephiroth's character to be dreaded throughout the game. Play Final Fantasy VII again, and you will notice that Sephiroth's presence is felt throughout the entire game, but he only actually shows up a handful of times throughout the course of the game. People do not even realize how infrequently he shows up in the game because his presence is always hanging over everything; this is an example of great character writing. However, every scene that he does show up is impactful, and the infrequency of it adds to that impact. Whether it be killing off an entire ships crew, killing a giant snake that is established to the main characters as unbeatable, appearing before the heroes as if to say "I'm here, and you can do nothing about it," he is meant to be feared by the player. He also does not have much dialogue, and while some of that is the infrequency of his appearances, he still seems to talk more in Advent Children than any one scene he is in throughout the game. Even when Cloud and co. take on Sephiroth for the final time in the Northern Crater, they're the ones doing all the talking; Sephiroth never says a word.
Some of these aspects of the character, such as discovering who he is for the first time, can never be replicated again. However, other aspects can be revived if only Square can remember what made the character so great to begin with. Gee, Square, I hope you realize this conclusion yourselves -- maybe you can one day remember what made your games so great.
