User blog comment:B214/General Discussion/@comment-201.239.133.207-20161226210534/@comment-29963364-20161228004847

in the Vali vs Azi Dahaka fight in vol.21, Vali achieved his DxD L Mode and unlocked Albion's [Reduce] poison.

What happened was:

Azi and Vali were having their fight, and they were interupted by a group of mass-produced Evil Dragons. This pissed them off, so Azi destroyed some with his magic, and Vali sent some of his Wyvern Fairies (his DxD L wings can turn into Wyverns) and had them release Albion's poison. The poison was in the form of a "dark mist." After coming into contact with the poison, the mass-produced Evil Dragon's bodies were slowly decomposed out of existance.

So Albion's poison might very well be an acid, but it seems more like a "poison mist" type. It might even be his unique "breath attack."

Ddraig can breath fire that burns even Gods out of existance. So maybe Albion can breath poison that decomposes them out of existance.