User blog comment:B214/High School DxD Born Final Episode Review/@comment-26428542-20150620185051/@comment-16281343-20150620191104

It's not it didn't had the chance. It's it can't.

That manifestation has more to do with Loki's curse. The small fragment was manipulated by him so it can manifest itself and move freely as it doesn't have any host anymore.

The power Rias showed is all hers.