Orochimaru's immortality Kinjutsu is based on Tobirama's Soul Transfer Kinjutsu.

[Nidaime Suiton]

The concept of Soul transfer in Orochimaru's immortality jutsu can from Tobirama's Soul transfer jutsu

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Orochimaru is known to have searched in Konoha's archives all jutsu and kinjutsu. That's why he have said that Senju Tobirama is the man that he respect the most. Because Tobirama has created many complexe jutsu, and as it happens the soul tranfer kinjutsu.

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Here we see Orochimaru affirm to Hiruzen that he make search about immortality

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What I mean isn't that Orochimaru's Immortality Kinjutsu = Tobirama's Soul transfer Kinjutsu.

What I mean it's that the concept of Soul transfer in this Kinjutsu is based on Tobirama's researches about the Soul transfer.

Because to be immortal, Orochimaru must transfer his soul in a body.

So I Think that Orochimaru used Tobirama's knowledges about Soul Transfer to create his Kinjutsu.

 

[SenseiSama]

And Tobirama's soul transfer jutsu is based off Uzumaki reaper seal which is based off Hagoromo's Human Path. All Senju and Uzumaki feats can be traced back to the Sage and Kaguya who Orochimaru wanted to be like.

 

[MomoSaka]

Nokun:

 

[Chikombo]

Maybe.

 

[Rikudou Tobi]

Soul Transfer technique is something Dan Kato copied, right?
Orochimaru's immortality spell came from the white snake powers. Rebirth.

 

[Urda]

Maybe.

This. Your theory sounds plausible, but there is nothing to suggest that Orochimaru was inspired by Tobirama or the two Jutsu are related.

 

[Reviewing Logic]

I always though Orochi originally had a frail body that would day at a young age

since his current state of always switching bodies makes his life way more shorter then if he just lived it out like Tsunade and Jiraiyah

but yes Tobirama was a very influential character for Orochimaru... it makes sense since he too experimented endlessly