We are excluding Wilhelm here. I'm thinking more science-y smart as opposed to tactical smart or that kind of thing.

For me:
1. Joachim Mizrahi - Reconstructed Lemegeton, created the Zohar Emulators and overall, in my opinion, presented as the greatest scientist in Xenosaga.

2. Kevin - Created KOS-MOS, T-elos and well...oh yeah, got into that university at fourteen (I think that's hwo old he was). Probably more stuff I can't remember.

3. Sellers/Yuriev - I'm not sure which one was smarter overall.

Hmm, well I don't know much about Yuriev's scientifical accomplishments, besides the creation of Omega. At least I think he was involved with it.

Anyway, it seems that creating Zohar emulators was something only Joachim Mizrahi was capable of, and he was depicted as someone other scientists looked up to, so my vote would go to him. He had some crazy gadgets on his list of merits like the Song of Nephilim.

Allen.

The only character with any common sense in the whole goddamn universe.

My vote would go for Mizrahi as well, for the reasons Athrun stated above. He was someone other scientists respected and looked up to, and the things he created were basically things only he could have done.

To me, Kevin in present time seems as smart as Mizrahi in old times. After all, he was Mizrahi's assistent back then, and if he was already that smart back then, surely he must have gotten even much smarter over time. But perhaps Mizrahi is still a bit smarter, nonetheless. As far as we know, Kevin can't create Zohar Emulators. =p

Sellers made one.
Though it lacked the stability in its power Mizrahi's Emulators had.

Wasn't Sellers' Zohar Emulator the one that caused planet Ariadne to disappear? Seems like a big failure to me, he hardly earned any credit for that one.

Nah. The one that made Ariadne disappear was one of the original 12. Afterall, it was put on the Durandal remember? 12 spots for 12 Emulators built by Joachim.


Don’t you remember? Sellers’ Emulator was in Omega which is why Omega went out of control and owned KOS-MOS


http://www.youtube.com/watch?v=qO8_Ykpa8KU

“Currently we’re operating using the spare emulator unit I constructed.”

I’m pretty sure what we see Omega eject before taking in the Original Zohar is Sellers’ Emulator.

http://www.youtube.com/watch?v=MZfvbl_kOnQ

Heh, I didn't remember. Whoops... my mind needed a little refreshment. Still, his Zohar Emulator wasn't on par with Mizrahi's Emulators, so it doesn't change my opinion much. Just that I'll rank Sellers slightly higher, but does that matter for such an underrated character? xP

Sellers had an inferiority complex. He's still more clear thinking than Kevin, whose entire emo spiral destroys any intelligence he may have had. Plus he was a douchebag. Douchebags are never amazing scientists, only good ones.

Sad but true. Even though he's whiny, he's probably one of the only few characters who seems to follow human logic. One of my favorite parts of the series was when I believe in Episode... II, they went into the Vector Restricted Area and stole KOS-MOS' weapon developed by Kevin (The E.S. Dinah is what it actually is). And Allen pretty much wonders if they should go ahead with this because 'Being fired will be the least of our problems' What does he get told? 'Man up Allen!' ... Allen would have been one of my favorite characters if he hadn't had such a silly crush on Shion, or had been less pathetic about it (He could've used some lessons from Tony, the way he hit on Shion in Episode I is great)

Mizrahi is definitely the most intelligent and likable of all of the candidates. Kevin is also one of the most intelligent up there, if in fact he created KOS-MOS and T-elos. While there isn't any reason to doubt it, I also wouldn't be surprised if Wilhelm was in fact behind the creation of both KOS-MOS and T-elos. But like someone else said, he's got a horrible personality and so I'd much rather chalk it up to Wilhelm actually creating KOS-MOS and T-elos... plus, it would make more sense for the final scene in the game to me.

I feel like including a Xenogears bit just because.

With Krelian as Xenosaga's Wilhelm, I'd choose Citan. He was pretty damn secretive, was a genius with weapons in way of having a major part to create numerous gears, including the Elements. Then there was the untested mech on the Yggdrasill which caused serious injuries but on his first way through it, he was able to "tame the wild horse". There was also the bit with "diagnosing" Fei, so he wasn't just a science nerd.

Anyway, like with others I would say Mizrahi is the smartest in Xenosaga. The Zohar, Realian's, including MOMO, then other trinkets like Proto Merkabah and the Song of Nephilim. I'm not sure if that was partially Sellers or Mizrahi, but one of the two brought about the Gnosis. Its been a long time since I've played Episode III so I'm not sure.

Well if you want to get technical... (Spoiler below)
The person who brought about the gnosis at Miltia was Shion, twice. This was likely orchastrated by Wilhelm the first time around, and the second time around (in Shions subconscious) by Kevin. Where the gnosis come from though, that's never really mentioned.

They come from the UMN. Because, basically, UMN is Gnosis.

Actually, Gnosis is the term given to anything from imaginary space in real space.
That's whY Abel's Ark is labeled a Gnosis but has no relation to the monsters attacking everyone.

Here's what it says in the database under Song of Nephilim:
"The Song itself does not have the power to summon the Gnosis. The Gnosis appear simply because a door has been opened onto imaginary space as a result of U-DO activating in response to people who have made fragmentary contact with it through the Song. In fact, the Gnosis who appeared around Miltia were actually caused by a fearful and isolated young Shion linking with U-DO and bringing the Zohar into operation."

As you can see, it seems to me that what the entry is saying is that Gnosis are summoned when a "door" is opened upon making contact with U-DO.
Shion opened that door wide open when she linked with U-DO and resonated with the Zohar.

The UMN is imaginary space, isn't it?

Man, this game and it's physical ##### calculus.

The UMN is the Collective Unconscious I think.
It's part of imaginary space, I believe. Not the whole thing.

The thing that doesn't make sense to me is the Gnosis's ability to turn humans into more Gnosis (as seen in Episode I on board the Durandal, where Rubedo shows the group the specimens of people who came into contact with Gnosis). They never really cleared up why the Gnosis could do that (or, in technical terms, turn real matter into imaginary matter, matter being a term I'm using for anything existing in their respective spaces) and that suggests that the concept of what the Gnosis really are was something that was changed throughout development of the Xenosaga plotline. Of course, I could have just missed the part where this is explained altogether.

Also, I'm pretty sure the U.M.N. is the complete imaginary space, because I think that the Collective Unconscious is what imaginary space is.

Ya, and no huevos!!!!! (well, I never played the second nor third... so maybe he has changed)

Kevin's madre turned into a Gnosis in the intro of XS3, so they still have that ability.

We just aren't told why.