Light Reincarnation Theory

There is the popular theory about the Unnamed Shinigami featured in the Death Note Relight 1 puts the theory of lights reincarnation.

The Unnamed Shinigami

Similarity between Light Yagami and Unnamed Shinigami

There is many similarity in both actions, appearance and dialogues.

Appearance

• He has a bag which is same as light’s high school bag.
• He has red eyes same as light’s red eyes at certain time in anime.
• He wears the same coat which he was wearing at the last when he died and the coat has blood stain.
• He has the red tie similar to lights sport red tie.
• In episode 24 when Light regain his memory after snatching death note from L's hands he speaks by the same voice as The Unnamed Shinigami and says: "I've won. just as planned!"
• Shinigami's eyes are identical to lights Simile when he wins.

Actions and Dialogues

• In the anime Ryuk tells Light that now he has something to look forward to after he dies. This stated many times in anime as the one uses the death don’t go to heaven or hell, the ‘now’ says that they go anywhere after death.
• The Shinigami walks into a bright flash of light at the top of the stairs.
• He walks with something on his limps stating injuries similar to lights when Matsuda shot him at the end.
• Ryuk speak in such way to Unnamed Shinigami as addressing Light. Ryuk speaks to Light as if he were there; "You were not God. You were just...gone already?".
• At the end of OVA, Ryuk says,” Wouldn’t you agree, Light!”. This shows that he is referring that Unnamed Shinigami as Light.
• The Shinigami doesn’t wait till Ryuk ends the story, as he already knows how it ends.
• In human world, Rem once says that Shinigami's digestive system is rotten or evolved so they don’t need to eat for living. Although, Light knows that only Ryuk likes the apples. He recalled at least some memories about Ryuk as he remembers him as a friend.

Thanks for spending your time and let me know your if anything I have missed in comments.