Gameplay concept for the next games main antagonist

I don't really want to get into the personality or motivations as to why said antagonist IS an antagonist. Instead, I want to propose a gameplay/narrative mechanic regarding how the main antagonist interacts with the player. I think it would be pretty neat if the next games antagonist not only attempted to capitalize on our failures, but also attempted to turn our own companions against us. Let me delve further into this.

Lets say you have a companion who falls along the lines of morally good. Throughout the course of the game, you take a number of morally evil actions that leaves the companion so distrustful and volatile towards you, that they end up leaving your party. Later down the line, the main antagonist comes into contact with said companion, and - through dialogue - are able to either recruit said individual into their ranks; or manipulate them to make your playthrough harder. In some respects, the main antagonist would behave the same way the player does, fulfilling a need of a particular companion in order to have them join their party. This could all pay off towards the end of the main story, where you not only square off against the main villain, but also your former companion(s).

Something else that could be cool is if the antagonist planted spies within the ranks of your ship. In-game, from your existing crew, 2 individuals will be randomly chosen to be the spies (1 non-companion NPC, and 1 companion NPC). Only a handful of NPCs (companion or not) have the potential to be spies, so it's not everyone. Maybe roughly 2/5 of the way through the main campaign, you - and you alone - get an encrypted message from someone stating that they have evidence to suggest that we've got a spy in our mists. You don't know who is working for the antagonist, and you have to suss them out by paying close attention to their responses, taking on small sidequests, and - potentially - garnering their favor in order to help build up their trust towards you. The more estranged this spy feels towards you, the more likely they are to sabotage key objectives you're trying to meet, or potentially sowing discourse between you and the rest of the crew. This would all take place throughout the remainder of your playthrough, up until the final act. You could accuse someone of being a spy, but without clear evidence or a confession, you'd not only set them free to potentially be an enemy you have to fight in the future, but it could also negatively affect your relationship with your other companions. You could tell someone about the message you received, but if you tell it to the wrong NPC, it makes it easier for them to fool you.

It would be a clever way of emboldening players to be more interactive with NPC's, allowing you to learn more about what makes them tick, and how you could potentially exploit those beliefs to find out who's who. The better you are at finding out who the spies are, the less opportunities the main antagonist has at putting you into a compromised position by the end of the campaign; as well as a less shittier ending.