User blog comment:B214/Volume 23 discussion blog/@comment-31764731-20170418200747/@comment-29963364-20170419162829

I actually have a thought on the "room to grow" line.

The DxD armors (both Issei's and Vali's) are "organic." Meaning that the armors are actual flesh now. So my thought is this:

Could Issei and Vali train to increase/improve the strength and power of their DxD armors? The "organic" armors could be thougth of as the "new bodies" of Ddraig and Albion. So maybe, just like how everybody can train their bodies to get stronger, Ddraig and Albion's power can still increase.

This way not all the pressure is on Issei & Vali training themselves to get stronger, but also on Ddraig and Albion.