no spoilers] The unique font used for Arcane is called Iron & Glass, and it was custom made for the show. You can see the whole typeset here! : r/arcane
Arcane - An Elegant Stencil Font | Free Font Download
Arcane's "VIKTOR" font? : r/identifythisfont
MB-Arcane Font : Download For Free, View Sample Text, Rating And More On Fontsgeek.Com