Copycat, meet Thief

"Roselia, Nadarus, Leviah.

Those are much, much better names than Pride, Greed, and Envy."

Somehow, despite the fact that Evan was a Hero, Leviah couldn't help but agree with his statement.

"I spent nearly a decade thinking about it once and I couldn't understand why you lot prefer using those names.

I for one, prefer using the name my mother gave me, rather than one that was added to my name after I awakened to my unique skill."

Clearly, Leviah preferred her normal name to her Sin Name.

"Did you get dumber than you already were over the past thousand years? I could have sworn I had told you exactly 57 times, that the reason was because of Alvey's damned brat and his lackeys who wanted to control us using our True names."

Leaving her not-so-subtle diss of Leviah aside, Pride wasn't just talking about their actual names, Roselia, Nadarus and so on.

She meant the 'Full' names, which when combined formed their true names.