Let us keep in mind that Amira appeared in Rage of Bahamut long before she showed up in Granblue.
Just like some other characters (Yggdrasil, Jeanne D'Arc, Yuel, and probably some others), that are originally from Bahamut, but even so, in the tags they have "_(granblue_fanyasy)"... It already reached a point where I just gave up on adding the "Shingeki no Bahamut" tag (and am not even sure if it was really right to add them in the first place)... . . . Sorry about it, but it really triggers me a little (as an ex Bahamut player, it's really sad to see Bahamut so overshadowed)...