the bad thing about GFs is that you forget things, but that could be a good thing (strongest one you can use Eden strongest in game grevier)
the bad things about Aeons you have to train them you know don't want to summon one and it kill you or run away. (You don't train them in the game just a joke)strongest one magus sisters
bad thing about materia the stronger it is the more mp it takes away. (strongest Knights of the Round)
each one is strong in its on way but i will go with materia, Knights of the Round is unbeatable
the bad things about Aeons you have to train them you know don't want to summon one and it kill you or run away. (You don't train them in the game just a joke)strongest one magus sisters
bad thing about materia the stronger it is the more mp it takes away. (strongest Knights of the Round)
each one is strong in its on way but i will go with materia, Knights of the Round is unbeatable