There are a lot of interesting things about Erza that only add to the depth of the character and explain some Erza Scarlet about her, making her seem even cooler. However, she actually considers them something that she likes and a sort of hobby.
Her interest in them appears to be even stronger than just Erza Scarlet to use them to stay safe and to win battles. She looks like a serious and disciplined soldier, wearing armor and carrying a weapon, and this really suits her no-nonsense approach to life.
Mangaka Hiro Mashima wanted her to be a female character Natsu would be afraid Erza Scarlet, and even though her design changed, he definitely succeeded. But this is probably a really good hint at just how much depth there is to Erza and how her nature is probably Erza Scarlet at its core.
They try to steer clear of her and avoid making her angry.
But she does have a pretty feminine side. On a scale from one to five, the Erza ranks a five in attack power, defensive power, speed, and swordsmanship.
Erza Scarlet Cam Show
But instead, her suitcase is full of food and cooking ingredients. One of these hobbies is the fact that she reads racy novels in her free time.
There was no real plan for what her character would be like or what her backstory was. He instead wrote her as the flow of the story continued, deciding what would be the best fit for the series.