How the new spy would work:
1. Choose a player to bug each night
2. The bug stays on that bugged player for the rest of the game (until they or the spy dies)
3. If something happens (e.g they were transported, roleblocked, attacked) to the player that you bugged, on the same night as they have been bugged, you will receive a message about it. If something happens on a later night, you will not know about it.
4. If a mafia or coven visits a player that you have bugged (either on the same night that you bugged them, or on a later night), you will be notified about it. You won't find out about mafia/coven visits to non-bugged players!
5. You can "re-bug" someone (for example if all alive players have been bugged). The only thing this changes is that you will receive messages about anything that happens to that player that night.
Some potential variations to this rework idea:
Possible variation 1: Instead of the bug staying on players for the rest of the game, the bug expires after some nights (e.g the bug stays for three nights). This would give more value to re-bugging players during the endgame
Possible variation 2: If mafia/coven visit the player that you bugged on the same night that you bugged them (but not on other nights), you will find out their roles. This would rebuff the spy slightly if my spy rework suggestion makes it too weak (and add more value to re-bugging players).
(EDIT:) Possible variation 3: Allow the spy to bug two different players on the first night that spy uses their ability (this would help the spy get started faster)
Personally I think it would be good to add variation 2 and 3.
Justification for the rework:
Currently spy is a somewhat unfun and uninteractive role (you get most of your information automatically without having to strategise), that hard counters a lot of night one random mafia and coven visits (which makes it way worse to play framer, disguiser, hypnotist, hex master and others...). The current spy also sucks for Executioners and Neutral Killing that are attacked by mafia/coven.