I've been farming mermaid DNA to get it to lvl 4... but when I reached lvl 2 it wouldn't let me use my complete DNAs (chains) anymore. It says "You cannot level up the Summon Level because of insufficient achievement recieved". In those exact words. A bit jumbles, but still, can anyone help me with that? Do I need a certain ammount of pets, or create new DNA chains and destroy the 2 I have left from lvl 1?
Please, help and thank you.