@Archieart He knows "You" because it is made out S3LF that he took from the other place. The "player" (that is also the name for "you") is supposed to loop in order for nevada to not fall, which is in favor of The Maker and also gathers info about mandatus and machine, which benefits Doc.
Everything I said is in arena mode. It will require to play like 4 times through arena from fresh character with no imprints.
AlfaFranek
Doc is not doctor and that was stated many times.
As for why is he working with the Maker and chosed "You" to be somewhat savior, then all we can tell is that they have similiar goal. "You" doesn't have a past, is one of the S3LFs and has only one purpose, to get more information on machine.
Archieart
But why did he know that it was “YOU”... Why did Doc know this?...He never even says that he contacted the Creator directly...