It would go roughly like this:
Origins: The cloud of smoke left by Miki Santana's incineration stayed solid and became a batter, and was assigned the random codename Fitzgerald Blackburn. When asked why they refused to dissipate like normal smoke, they said they wanted to experience the world.
Agency Work: Blackburn's amorphous form can fit into extremely small spaces and escape from any room that isn't airtight. Blackburn is also excellent at telling when people are lying, but that's because of empathy that they've had to learn to control.
Blaseball Career: An acceptable batter who slowly improved into an excellent batter over the seasons, Blackburn remained a constant of the Spies roster until recently. Until season 13, their equally excellent pitching ability was highly classified.
Scattering and Trades: After Theodore Holloway's death, Blackburn let themself be swept away by Flooding and despair. They were traded to the Lovers to recuperate, where they proved to be an incredible pitcher. The next season, Fitzgerald was sent to the Spies' shadows (possibly due to paperwork interference).
Relations: Math Velazquez is in the world for the same reason as Blackburn is. A mutually supportive queerplatonic relationship with Alexandria Rosales. Confused and distressed by Hotbox Sato's existence. Refuses to talk about their relationship (or lack thereof) with Knight Triumphant.
