Because Lyon needs more attention. XD
So @Sharia 's question yesterday was really interesting and honestly I don't know why the others tortured her but I found the reason why Dimaria did it.
The similarity between those two panels cannot be unseen. Dimaria is a confident and strong lady whose pride was wounded when she was defeated by two young girls and then captured by the enemy. "Corrupting her Randi" is not the only reason she's doing this to Lucy. She's holding a grudge against the Fairies and wants to get back at them, to give them a taste of their own medicine. I find that a very interesting trait of hers. Can't wait to see how Mashima will further develop her character. source : taleen777