We once needed to complete each quest with item rewards on FOUR different characters – once for each armor type – to earn all of the possible amor appearances for possible quest rewards.
Is that still the case, or does completing a quest ONE time on one character (regardless of class) now earn ALL of the appearances for all possible rewards for that quest, even for armor types and weapons that character cannot use?
As far as I know, one quest gives all now but some might be bugged/disabled for some reason and there’s no real way to know unless you look up that quest to see all possible rewards and if you have them.
I have an old vanilla-made Druid that completed vanilla mulgore quests back when I was youthful and spry and it unlocked mail transmogs for me when they enabled that years later. Same with the main campaign quest in TWW - I did it on a mail wearer and it gave the set pieces for the other types.
Most quests unlock the appearances of every available reward, regardless of what gear is available to your character specifically.
There are a handful of exceptions, for example the quest in Hallowfall that rewards the cosmetic torch maces only offers either the lit or unlit version, and you need to complete the quest again on another character to get both.
But in general, completing the quest on a single character awards every appearance any character could get from that quest.
There are certain quests in the game that gave unique recipes / patterns. Requiring you to do certain quest chains 2-20 quests long to attain the item on the right character, with the right professions.
Legion has a small chance for the Codex rank 3 from bosses and caches from reputations. I think profession specific.
Most things are now do it once and you are done.
If you are a completionist you will still need to do class specific quest chains.
Faction/ Zones questlines.
As certain zones have their own lore for both factions.
I think there are a few more examples (overall) that I cant recall at the moment.
Utilizing the website. Dataforazeroth.com
Will satisfy all your completion needs.
You can add your entire account through a queue system and then see exactly what you havent done on your account.