So I was just thinking what If kishi decides to keep madara around how he go about it(and no madara disappearing and being resurrected does not count).
Its has to be izanagi whichever way you look at it izanagi is the only technique that we know of that can save madara. I think madara will revive himself because even though he's soul is bound to the real word he is still technically dead and he will lose 1 eye.
But after being resurrected he will have his other eye back or if he dosent get his other eye back he will simply go and transplant the other rinnegan tobi has. After all it is his(baecause he is the only we know of to actually awaken the rinnegan) so he will just transplant it and since its his rinnegan he will be able to switch from sharingan to rinnegan with it.
Its has to be izanagi whichever way you look at it izanagi is the only technique that we know of that can save madara. I think madara will revive himself because even though he's soul is bound to the real word he is still technically dead and he will lose 1 eye.
But after being resurrected he will have his other eye back or if he dosent get his other eye back he will simply go and transplant the other rinnegan tobi has. After all it is his(baecause he is the only we know of to actually awaken the rinnegan) so he will just transplant it and since its his rinnegan he will be able to switch from sharingan to rinnegan with it.