User blog comment:FairyRaven/Fairy Tail Chapter 344: Wizards vs. Hunters, Review and Commentary/@comment-5598380-20130719082836/@comment-77.195.192.254-20130719084636

I don't think the ice weakened Erza, I think this ice has a consciousness and the power to turn the one who touch it into what he / she is in reality. Erza thinks she is an adult but in her heart she is still a child ( following all the events in her life ), the ice sensed it and turn her body to match what she is in her heart