I just finished FE Blazing Swords : Hector mode today and I decided to start FE Sacred Stones. All was fine for a while, but around chapter 2, the one where you get Ross and Garcia, I realised my Eirika was getting weird. When i ask her to attack enemies, she would just raise her sword. No damage will register while in combat, but they'll die once out of the combat screen. (I also noticed her Str stat has changed to Mag) I looked around for a long time and it seems people says this problem stems from hacking the game, but I've never hacked the game at all, I don't even know how I would go about that.
So my question is, why is this happening and how do i solve it?