After finishing the quest "Ultimate Weapon", I obtained the item "Armor Identification Key", which I immediately used,just before a cutscene started.No message or notification appeared , but afterwards I used Mount Roulette and got Magitek Armor despite not being registered in my Mount Guide.Currently the only way for me to use the Magitek Armor Mount is through the Mount Roulette, since it does not appear in my Mount Guide even after logging in another day.