>>1588172Strangely, Erza didn't begin the series as the big fanservice draw. That was originally Lucy's role and stayed that way for quite some time, until it became more and more apparent that Erza was the most popular character.
With the softening of her character and her more lighthearted goofy elements coming to the fore (with the exception of whenever Jellal is seen, heard, mentioned or thought about), Hiro saw the opportuniy to really push her as the main purveyor of T&A in official art.
But for fanservice in the story proper, Lucy's still the go-to girl.
