Sasarai is staying in Thorne and will not try to convince anyone else to stay with him. He doesn't trust Thorne but based on his limited understanding of this world so far Thorne is a lot like Harmonia which means he feels like he can navigate the political landscape and survive and thrive there well enough to do some good.
He would be interested in routinely meeting people who leave at Horizon once he learns to access the place as a way of sharing information. He might try to convince people to reach out to him from time to time before they leave. This might mean asking someone untrustworthy but Sasarai is not above finding ways to socially crush anyone trying to make his life difficult. He's a war-time politician, after all; tiny but ruthless.
Obviously, this all means he's keeping a personal tally of who goes where. In all of the chaos he won't be able to keep track of everyone so this tally is opt-in only. Let me know if you want Sasarai to have a general knowledge of where your character went. Keep in mind him knowing might mean someone else in Thorne knowing in the future, depending on how things go in game.
Sasarai | Thorne but kinda sneaky
He would be interested in routinely meeting people who leave at Horizon once he learns to access the place as a way of sharing information. He might try to convince people to reach out to him from time to time before they leave. This might mean asking someone untrustworthy but Sasarai is not above finding ways to socially crush anyone trying to make his life difficult. He's a war-time politician, after all; tiny but ruthless.
Obviously, this all means he's keeping a personal tally of who goes where. In all of the chaos he won't be able to keep track of everyone so this tally is opt-in only. Let me know if you want Sasarai to have a general knowledge of where your character went. Keep in mind him knowing might mean someone else in Thorne knowing in the future, depending on how things go in game.