This of course means I cannot see any warnings, posts or general nonsense he tries to send my way.
Don't worry - you'll still see warnings as those are not tied to anyone's account! As for explanatory posts, you luckily always have the option of revealing them on a case by case basis (if you're reading this - congratulations! 🎊)
[EDIT: As a fun aside, I just tested it and it turns out I
can still PM you, so that's gonna be pretty ineffective. Not that I ever would, I pretty much only use the function to reply to others.]
Unfortunately, we do not delegate mods to individual members. If you don't want to see warnings, stop misusing S&C. If you don't want to lose PM arguments, simply don't start them.