This is just speculation on my part based solely on what I've seen on the Terminal Disc and my own assumptions of the series.

Project G.U. was created to bring back Aura after she left near the end of R:1.  All eight phases were pulled from the sea of data that was The World in order to give birth to her when they were brought together.  So, this is my conclusion:  Haseo will give birth to Aura in Vol. 3 after he has data drained all of the other phases and assimilates them into Skeith.  Then we have the new time of peace for the world.

That is all, thank you.

When the six go visit the Serpent of Lore, is that Yata infected with an AIDA?

Oh and who is that grey-haired girl(?) in the rocking chair?

Gray-haired girl usually equals Aura to my knowledge

-Corbenik is back
-Haseo temporarily becomes AIDA-PC

New specualation Skeith 3rd form is a result of everyone transforming at the sametime if you listen carefully. Also AIDA-PC Haseo is probably what makes him lose his Adept Rogue form and forces him to become Xth form.

the girl is called enma (or something like that) and she is the one that introduced Phillyo to Ovan

girl in rocking chair does not look like aura at all, so i doubt her being aura. and.. well i do't know much of anything, but it does seem like Xth form is gonna ROCK!!!!! and yes! what i suspected seems to be true, I always tho that X form was not part of hasseo, so some outside force made him that way, Mainly Aida :)

maybe skeiths power is to contorrol  an A.I.D.A  infection as "riding the wave is skeith" and skeith 3.0 is the result of A.) Haseo data draining all the phases or B.) a union of 7 phases

and yes the AIDA infection dose leed to the X-form but it is unkown if there is more to it (a Skeith AIDA for example)

The 8 energy sabers on Skeith's back strongly suggests that Skeith's third form is an amalgam of the other 7 phases. Notice also at the end of the trailer, you can see Kuhn, Endrance and Atoli with their epitaph markings calling out Haseo's name.

What's a little odd is that some of the epitaph users were left out of the "Ore wa koko ni iru SKEITH" thing... I definately heard Haseo, Atoli, Endrance and a 4th male voice I can't put my finger on.

It seems Sakaki is coming back too?

kuhn. --^ .. kuhn is the 4th. "Ore ha, watashi ha, Ore ha, Boku ha,  ... koko ni iru.. SKEITH!~~~" .. Haseo, Atoli, Kuhn, Endrance.

@b4k4ni04: lol... transate that please?

... .... .... .... .... .... .... on the premise that i'm merely repeating what is said in the trailer. no.
I'm only stating the order which is:
 Haseo, Atoli, Kuhn and endrance "Ore ha,(<--haseo) watashi ha,(<--atoli) Ore ha,(<--kuhn) Boku ha (<--endrance)... koko ni iru. SKIETH!~~~~ ;P.

<Ore ha, watashi ha, ore ha, boku ha.....koko ni iru. Skieth~~~!!!>
Its order doesn't really make that much sense in english but its something like this
"Sheith come......to me, to me. to me to me!!!"
does't sound as good in english

LOL.. I noticed >_> it doesn't sound that good, nor does it makes much sence... but it does sound weird how other epitaph users are calling skeith >_> new power they found? I think that if they would translate for the game.. It would be something more like "In me! in me! in me! In me! Awaken! Skeith!" >_> but it still doesn't sound good.

Couldn't this be like Haseo's "It's here" speech?

bah.... Shuhei I must vehemently oppose your translation. there is absolutely no direct mention of the verb "to come" implied perhaps, but as you have proved yourself it makes for a rediculous translation.

I'm, I am, I'm, I am ... here/right here... SKEITH! ...

meh . ~b4k4 needs sleep z_z.

 um Spoiler/Theory

  my theory on how haseo gets his Xth for is first he obtains Data Drain in while in 3rd form (still looking to find out how) hes uses DD on a very powerful AIDA or abuses the uses and he gets infected, or  ADIA Ovan uses that cannon to infect him and then he becomes an AIDA PC then which either an epitaph user or i think the Azure knights DD him and this is where u see him lying in the desert at which Enia/Aura shows him in Xth form says all this i can grant u the strenght and power then shazzam  you get Haseo Xth form as for the avatar awakening i think the reason they all yell is cuz its to reasure Haseo when he starts his fight against Cubia Alpha.... P.S. Cubia i Belave Sakaki put the red egg looking ADIA In him which might be the (EGG) Cubia Alpha resides in then events lead to him dien and Cubia being release.......... thanks for your time hope u like my theory and im sorry if i mad some of you mad i just wanted to let someone know what my opinion is on what  happens in  Vol. 3.....

the translation is im right here Skeith, thats common sense i mean he says it everytime...how long have ya been paying attention to .hack...
and thats because haseo can't bring out skeith so they all assist him in summoning skeith to kick Sakaki's avatar's ass...ok?

actually, he confronts skeith and when the "fight" ends, he "fuse" with skeith to reveal the new Haseo Xth

Ya. Basically 'Skeith' or "The Terror of Death' as he calls himself, looks like Haseo's 3rd form, only with inverted colors. (Armor is white with black tips and hair is red instead of silver hair and black armor with red tips.) After a long cinema, they fuse and the Xth form is created thanks to Zelkova's tampering with Hasoe's PC.

U guys have gotten it all wrong.......... after haseo defeats ovan ovan uses his special power to restart the net and thats why he "dies" and `cause haseo was the closest one to him "except for Aina , ovan`s sister" he got dammaged his pc and thats when they found him on that desert later he confronts his "alterego" skeith and after that the fuse and before the completly fused Zeñkova hacked his pc and added him new powers a new gay hairstyle and some new hella cool weaps ( DG-X) and now haseo uses the dual swords the broad swords the Schite and the new dual guns oh...........

SPOILER

Haseo beats up cubia whit the power of all the other phases and then he recives a e-mail from tabby and u get to play the event of "the forest of pain" and hoe u must know by now a normal dungeon its made from (max.) 5 blokcs but this has got more than 60 blocks right now im on blick 64 and i think it will have way more than 100 blokcs.......could someone tell me how many blokcs it has got?