What happened to tartarus?

[Al-Kun]

Yes, what happened to it, after Nyx defeated?

"same Question":
http://www.atlus.com/forum/showthread.php?p=83024#post83024

[Violinzu_Hiromi]

It still exists. The only thing is that the world no longer undergoes the Dark Hour.

[septembervirgin]

Perhaps the Dark Hour might be restored by a clever scientist. After all, it seems useful.

[Gen Eric Gui]

It's easy to restore it.

Just get rid of Minato's seal. Of course, you'd have to get through Elizabeth to do that. And of course, restoring it would bring about the end of the world.

How would that be useful?

[Riku Xander]

And good luck (to most) getting past Elizabeth.