User blog comment:Mckrongs/Monster Variations/@comment-1011548-20130917105957/@comment-8874090-20130918172842

As you said Fatalis are not considered subs in-game. You can see that when you accept a quest with them. Unlike usually, when the subs name is written (e.g. hunt an azure rathalos), it only sais "slay a fatalis", even if they are crimson or white. Never understood why, though.