The player is Horatio from Endless Space
Horatio authored the journals, influenced the team loadout, and, as shown in the comics, is canonically present but not a hero. He's shown healing the team in the comic (which the player can do directly) and a super-genius like Horatio would see the "overview" of the situation. He's smart enough to stay out of trouble, so that's why he's effectively invisible (he wouldn't consider himself a pawn on the board). The player also "joins" the team after the crash, not during, just as Horatio does.- Posted on the Games 2 Gether forums and confirmed by Word of God.