Once a group singles you out for any reason (whether through OOC not wanting you in their community, deciding they just don't like you for whatever petty reason, etc) they will hold onto that grudge for years and never change their mind. How pitiful of a person do you have to be to oocly try to target and force pk someone's character? People's ego on this server never ceases to amaze me.
It should be noted that these kinds of people aren't stupid by any degree. Of course they are going to use VCs and strict private chats to target someone. As long as there's "plausible deniability" mods won't do anything. What's worse is if there was/is staff involved with people that were doing the targeting. Sorry, but there's no shot you'd be able to do anything if enough staff got together in defense.
Thanks for pointing out the issues of LOTC before your leave, there's a chance it could have some impact on the future. May your departure/break/whatever you decide to do contribute to your irl wellbeing.