If you are unhappy with how things have turned out after reading Immortal Regis, just keep reading. Starting from chapter 24 you will have some explanation.
How come she is level 3 after killing all those monsters? The sword didn't do everything but Fran definitely did something on her own while swinging the sword.
How come the ovas released are POV? I thought that just the maid from the ova was similar to this manga but every detail of her dress is exactly the same.