First off, Kushina, yes maybe.
By the way, I think coffin is the word you're looking for.
The only person we saw was Orochimaru, and that was because he was revived through another medium, AKA Anko's Curse Seal. The Orochimaru that was saw against Itachi is still sealed in a sense, and he used his own jutsu that had part of his senjutsu and soul to revive himself.we saw people that were unsealed or revived even though their soul was sealed.
The biggest thing Tobi really cared about is how to stop it if it was ever needed. Im sure his (and all of our) first thoughts were "Kill the King, Lose the Pawns" but Kabuto said that killing him won't stop the jutsu.Watching the Edo Tensei technique process didn't have a really good purpose for Tobi, but for us to know:
First: You get the living sacrifice.
Second: After some ritual, you summon the soul of the dead you want to revive
Third: The living sacrifice takes the summoned dead apparence.
Fourth: The revived is sent to fight or put in some box(I don't know the English word...)
By the way, I think coffin is the word you're looking for.
Kabuto never said exactly what happens when you try to revive a sealed soul. According to what we can learn from Orochimaru, its either:During Orochimaru vs Hiruzen fight, Orochimaru summoned the First's, the Second's and was about to summon the Fourth's box(well, this is awkward already...). How did Orochimaru have that box if the soul was sealed? This is my question.
- The box appears, and then swiftly disappears (meaning Hiruzen didn't do anything to stop the jutsu)
- The box appears and it comes out empty or the ruined sacrifice intended to use for the jutsu (meaning Hiruzen did stop the jutsu)