Who accidently is sent back to his teen and changes the world with new tech.
Never heard of a scintist, is that some sort of specialist for the Scin gene?
I scintist is someone who studies the seven deadly scins.
John The Genius series by PT Brainum has a child prodigy who can see all possible futures. No need to do the experiments that don't work.
https://storiesonline.net/series/1434/omniscience
Paul's Redemption by Nova Scriptus has an antisocial genius retreading his life. As with John Wales' hero he 'invents' the laser.
https://storiesonline.net/s/53355/pauls-redemption