FileBot

I used FileBot to get some really atrociously anime file names sorted out, for PLEX. But this is what I wound up with.



Should I have taken other steps to get a better result? Is the current best way to deal with renaming anime for PLEX norms (by seasons)? viewtopic.php?f=3&t=2769

Yes, standardizing everything to TheTVDB naming and numbering will do the trick:
viewtopic.php?t=2769


Plex will expect you to name your files like so:
https://thetvdb.com/series/re-zero-star ... official/2


If Plex still doesn't show nice metadata despite correctly naming files, then there's probably something else going on as well (e.g. caching would be the usual suspect), best to check with the experts on the Plex Forums for these kinda issues:
https://forums.plex.tv/