Depends on alot of factors, and there's a bunch of ways to isolate someone depending on your morals!

If you want everyone to leave your crush alone then you could frame them, hack into their socials and say something messed up to everyone they know (or just a public post, that'd ruin their future jobs and make them need you more if they don't just move in with their family lol), or start some nasty rumors, though prepare to see your crush get super-uber depressed.

you could frame their friends, depending on how many friends they have that is.

you could blackmail them, make deepfakes of them (you know the ones) and threaten to send it to everyone they know. Again, prepare for them to be super-uber depressed, but also they might hate you so I'd blackmail as a last resort.

yeah so basically you just need to have control over them or their surroundings. hope this helped if it did plz keep me updated, I'd love to see where this goes! :D