About reaper death seal...

[Apexx]

Can edo tensei use it. If so Hiruzen can still use rds on madara.

 

[Braveknight]

you need to be alive to use it

 

[Thundergod123]

you need to be alive to use it

It only takes away your soul so you can still use it, because a user like Kabuto needs their DNA and soul to perform it.

 

[Apexx]

Edo tensei have souls.

One way for edo to be released is for soul to have change of heart or something dealing with emotions.

 

[jediknite2]

I think u need to be alive else minato or hiruzen would have attempted it already.

 

[Apexx]

Plot no Jutsu?

 

[SSS12]

Probably not. IF they can, maybe that's why Minato lost his arm(s). Minato could get Madara with his intellect and speed with RDS. Hiruzen lacks the speed.