Within Bioshock AU, Tyson is given the nickname/trigger word Pup as part of project Blind-Faith; funded by a man claiming to be called Jim Moriarty.
Where Tyson is spliced with Telekinesis, Electro Bolt 2, Peeping Tom, & Blind-Faith, The Colonel is spliced with Old Man Winter, Gravity Well, & Incinerate! With the exception of Blind-Faith, Tyson and The Colonel were the ones to inject each other with those plasmids to help the First Bangalore Pioneers schemes.
Additionally, in his work for Moriarty, Tyson has been given the Gene Tonics Natural Camouflage and Brain Boost to make him more useful in the time remaining before he is thrown away as an abandoned test. He’s a useful guinea pig for the time being.
Tyson lives in a shoe box apartment in Pauper’s Drop. After completing his work for Moriarty, Tyson limps home to lick his wounds in squalor before being called out again to complete his dirty work. He’s an old hand at hacking the various machines around Rapture to pool together resources and enough money for food.
He hates living in Rapture. He never even wanted to come to Rapture. Tyson was brought in with a wave of works to take care of Rapture’s bountiful troubles, specifically to work with the Atlantic Express, and later found himself stuck at the bottom of the ocean, and not long after without a job as he was replaced by a wealthier engineer who bought out Tyson’s position.
Tyson would give anything to go back to the surface. He feels cheated and alone, and he’ll throw himself at anyone who offers the tiniest piece of kindness. The Soldier, on the other hand, is completely loyal to Moriarty’s cause; unlike the normal Soldier, he would absolutely sabotage Tyson’s attempts at freedom.