Mafia 90. The Tale of Oldforest.

I have something similar planned for Sailor Moon. Some roles are initially clearly weak or mediocre, but when a catalyst joins them, they become extremely powerful. But here, the situation is somewhat different. I can't imagine a lone player who can win with anyone. When would they decide who to win with? Do they send their preferences to the GM along with the non-declared roles on the first night? And what if the lone player wants to win with the Mafia, but the Mafia, unaware of this, eliminates them?