This is for all Seto Kaiba fans!  If you love Seto and if you really would like to know where he is currently in the anime, then keep reading!!!  You probably know that Seto appeared and was mentioned in Yu-Gi-Oh! GX several times.  In fact, if you’re looking for a very detailed summary of the GX episodes where Seto made appearances, was mentioned, was in flashbacks, etc, then please visit:
http://brotherlyfluff.deviantart.com/art/Original-characters-in-GX-Pt-2-99659511

The last time Seto actually appeared in person was in GX episode 76, when he spoke to Sartorius.  Also, the last time he was seen in a flashback was in GX episode 107, when Aster Phoenix mentioned how Pegasus believed Seto was the second best duelist.  GX episodes 156-180 were not dubbed, so those who watched all 180 episodes had to watch the last season in Japanese.

In GX episode 168, Axel Brodie found lists with names of people.  Whenever people were sent to the World of Darkness, their names disappeared from the lists.  The enemy, Trueman, was responsible for sending them there.  Axel tried to call a Kaiba Corp employee to see if someone was in the building, but no one answered because workers were also disappearing.  There was another list next to a Kaiba Corp computer and the names on it were disappearing from bottom to top.  The name on the very top said Seto Kaiba.  However, when the name below Seto’s disappeared and when Seto’s name was about to disappear, the scene changed.  Many fans say that Seto’s name did not disappear, but I am not 100% convinced since the scene changed at that moment.  In other words, I believe we cannot be sure what happened to Seto.  If he did disappear, then he would have been sent to the World of Darkness.  Jaden saved everyone from the World of Darkness in GX episode 178, which would mean that Seto would have been saved.

However, let’s say Seto’s name did not disappear.  That would mean he would have stayed in Domino City.  In GX episode 170, Sartorius and Jaden went to Kaiba Corp.  Then Sartorius revealed to Jaden that it was a trap and that bombs had been set up at Kaiba Corp.  The switch would activate the moment someone tried to step out of the building, so he forced Jaden to duel.  In GX episode 171, Jaden won, but unfortunately the bombs exploded, causing Kaiba Corp to blow up.  In GX episode 172, the explosions continued to destroy and burn up Kaiba Corp.  If Seto was in Domino City and if he was in Kaiba Corp, it is unknown if he died.  However, if he was in Domino City but not in Kaiba Corp, then he must have been horribly furious when he found out what had happened to Kaiba Corp.

In GX episode 179, Seto was seen in a picture on a piece of paper that Jaden picked up.  However, that doesn’t tell us anything about Seto’s current whereabouts since Jaden had travelled in the past when he saw that image.

Kaiba Corp was shown again in Yu-Gi-Oh! 5D’s with a new design, but so far Seto Kaiba has not been mentioned as being the CEO of that Kaiba Corp building.  It is also unknown if Seto was the one who designed the new Kaiba Corp.

It is a mystery when it comes to what happened to Seto and where he currently is in the anime.  Please feel free to post your comments on what you think may have happened to the amazing Seto.