User blog comment:Jopjopjop/Volume 18 Spoilers/@comment-24019927-20140619135304/@comment-1359322-20140619143953

She's still stronger than most, plus she's still growing, once she masters her Extinguished Star, she'll be able to become stronger.

Also if your just counting the peerage, then Asia would be the weakest undoubtedly, she's practically useless in a fight without her familiars after all.