How Erza escaped from Tartaros dungeon?
One thing that we never see in the anime or the manga is how Erza escaped from her shackles and beat Yakdoriga. The official wiki describes it like this:
“Some time later, as Yakdoriga guards Erza, Lisanna and Natsu -imprisoned elsewhere in the Tartaros headquarters- manage to break free with the help of a Heat Blade. Finding Erza's cell, the two barge in and succeed in freeing Erza from her restraints. Now able to use her Magic, Erza Requips into her hakama clothes and attacks Yakdoriga, knocking it unconscious and gleefully wearing it over her shoulders”
However, that’s not how it appears in either the anime or manga, and the story does nothing to directly tell us that they actually rescued Erza. You know what I suspect instead? Erza suddenly remembered Kyouka ordering Yakdoriga not to touch Erza otherwise her efforts would be for nothing, and decided to take advantage of it by tricking Yakdoriga into disobeying that order, causing him to set her free by accident, and then attacked him. Because, the actual chapter/episode made it seemed as though she escaped on her own and did not need Natsu or Lisanna to rescue her. And they attempted to only to realize she already freed herself.