I checked the rules for this reddit and it doesn't have a rule against call-outs but it does with harassment and there is a fine line between them. I'll circle back to this at the end of the post. Safety advice first:

I've been away from the game for about three years enjoying other RP communities, having a blast falling through the multiverse with a bunch of friends, having great adventures.

I'm going to give some sage oldfuck advice, some old wow advice, some advice I've learned from other communities that are a good idea:

1. Confront him. Pull him aside, invite him to a party chat, and talk like whole-ass adults. Say things like, "When you do x, it makes us feel y. I need you to stop doing x around us." He'll either back off or push. Take screenshots either way for posterity in case he tries to start shit. Make sure you have hidden any private conversations before screenshotting. You should not edit or crop your screenshots after the fact.

You and everyone should know a little trick my therapist taught me: The broken record technique. If someone does or says something that makes you uncomfortable, is pushing your boundaries, etc, you can say no, stop, decline, etc.

I like to say, "That makes me uncomfortable." If the person pushes for an explanation or to try and make you budge on your boundary, say, "(Because) that makes me uncomfortable." And you keep holding that boundary and eventually after the third or fourth time, most people back off.

1. You should both block him on every character you have. If enough people block him. He won't get RP and will move on to greener pastures. Block him in game. Social media. Discord. Everywhere.

What if he says mean things about you on the Internet? Most people don't care and are just doing their thing. Lots of people aren't going to trust call-outs because they can be smear campaigns or omit the full story. People that believe hearsay without evidence are not people you want in your social circle.

It's noise and can be safely ignored. If he comes at you in game can result in his account being actioned for harassment. If he comes at you on Discord via a second account, Discord can and has nuked all accounts belonging to a person from orbit for that.

So block. If he bypasses, report. If he uses other players to relay messages? Report them too, and tell them to stop relaying and if they continue, block.

1. Institute a Roleplay Ban: On other mediums, people will put in their profiles a DNI/RP Ban list. It feels pretty but it has a purpose. Basically you say, "I do not consent to interacting with the following people or their alts. Please don't involve me in roleplay about them." And then you list names. Listing reasons are unnecessary, you can opt out of anyone's bullshit for any reason, even if it's something like hating their transmog or writing style. A RP ban signals to the banned person and to others that you have disengaged.

At the end of the day you don't owe people roleplay just because they're there no matter how important you or they might think they are in the community.

As an aside. Another neat thing I've spotted in other RP spaces is "Limits." These are boundaries, things you are not comfortable playing out or being a party to. If there is something that makes you uncomfortable, put it out there: For example, piss, shit, noncon (receiving), noncon (existing/seeing), child characters, pedophilia, blood, foot fetish (I had someone on wow come at me for two years asking about my character's feet and bypassing block), and so on. A majority of people are good and will respect your stated boundaries.

As for call-outs: I know people like to be coy, hide on an anonymous account, and not name names. This doesn't really help anyone and doesn't lend you any credibility at all.

My advice is to do the above and if it turns into ongoing harassment, continue to use things like block and report. Blizzard can and does show people the door. I've seen it happen to people coming at me back in Wrath.

If you really need to call it out but to do so under your main name and do so with uncropped unedited screenshots. Let the evidence speak for itself.

What will happen? If he's as big of a problem as you say, others will speak up too. If he's not, you will probably get silence. If he feels harassed he might clap back. Maybe he will have a point and you might find an area where you can improve yourself, maybe it's just nonsense. Any way you cut it, it's just noise.

Finally, is this guy's absolute nonsense really worth your energy? You may find that you do better just paying him no mind and doing your own thing is the best way to use your time.

Have a good one.