MTGNexus

I don't mean necessarily whole other character sets, I mean just things like diacritics, thorn/edh, ligatures, and things of that nature.

You can't use such things when doing card evaluation. (Which is kinda funny, when originally æther was a pretty relevant word in lore and even showed up, with diacritic on card name.)

It's a mild annoyance more than anything that has to be fixed.

Apologies for not responding, my computer is down and I missed this.
I'll look into this, it seems to be a bug in encoding the characters.