Dealing with trolls is counterintuitive, because they're doing it all for the attention. As long as they keep getting attention (and reactions, like this post) they are more likely to keep doing it.
This troll is probably reading meta right now and having a jolly good time about the chaos they're causing.
To deal with them, I'd recommend:
- flag as spam their posts
- custom flag their posts to make the moderators aware
- do not post on meta the moderators and broader community are aware at this point
- otherwise ignore the troll and their efforts. If if stops being interesting for them to continue trolling, they are more likely to stop.
You can safely assume that the moderator team and community team is by now mostly aware of their activities, and the charcoal project has started adding filters for their shenanigans. With some luck, fading back into obscurity and normalcy will mean they stop.