Why is he having existential crisis now lol. This has been brought up by Sensei before. Everyone, who has been revived, is basically a clone. Kurono, who has been revived twice, should have accepted that fact a long time ago.
Nah gang, fuck all that THEN WHY DID U SMASH?!?! He tripping over some shit he didn't trip on with Kishimoto. No matter how much development, Kei can never relinquish his selfish nature (ofc Reika is also selfish as fuck, but that's why they match so well)