Oh definitely, he isn't going to stop at a block. It's just too effective.

A total nuclear approach is probably the only thing that'd do it, if you play whack a troll (check profiles as they're built and their first posts etc) and yeet their asses before others take the bait. You'll need a united front for that though, as it's much harder to vet newfags on other federated instances. People blocking/muting, when kicking around his tumblr persona gets boring, is what I'd recommend. Maybe throw him a badge saying "Don't feed the trolls"/"Parody" or some shit.