User blog comment:Jopjopjop/Volume 19 Spoilers/@comment-3965848-20150510080407

I think I know what Asia's BB might be, her BB have the ablility to heal sevevered limbs (without any help) and cure deseases and poisons, that could come in handy if ever faced against Samuel's curse and Yamata no Orochi's venom again.

Another ability it could do is increase stamina which could be a big help especialy to Issei.

And maybe even create a huge field of her healing aura, effecting only her allies.

This is just my guess of what it could be.