let's play a game
Tommy was once a slave. That's gone now - shoved in his past with the memories of blood and gore and death. He wants to forget who he was; what he has to do to survive.
Of course, the Elementalists will always come back to haunt him. They aren't the ones who killed his mother, but they're close enough.
And now he and his brother have been dragged into the mess, as Elementalists with their own, separate covens, to find the Pit - the place where he'd lived and killed and hurt for the first twelve years of his life.
His coven can't know. Can't know who he really is, what he can really do. Can't know anything about his past.
He doesn't want a coven full of Elementalists who don't trust him; one of whom he's pretty sure despises him. He doesn't want that life.
He wants the life of a pickpocket, on the streets, because nobody questions street kids, and nobody comes asking about his past and pushes him to tell his secrets that he holds closest inside.
Tubbo tries to tell him to trust people.
But trust is how you die.