Any graph showing Frost ahead of Fire (Even Single Target) is incredibly bad. Fire is nearly as good as arcane in single target at BIS due to ridiculous Mastery levels. Frost can really only burst about 300k on ring prices where Arcane is pushing 1mil and Fire about 700k. By the time Fire damage starts to level off, Ring is up again.
As to the original question, Fire is looking pretty decent in Legion, but generally is better towards the end of expansions due to scaling. Not sure how the other classes look.
This post was edited by Songhai on May 27 2016 04:32pm