User blog comment:B214/Volume 23 discussion blog/@comment-77.188.244.180-20170422145726/@comment-190.160.185.214-20170422163337

i don't think it's forbidden since no one has seen  it other than Sirzechs, it was a sealed move and i don't think he can used it outside of DxD form, at least for now...the thing with Ddraig's flame and Albion's poison is that they themselves don't want to use them in battle since their aim was to prove that they were powerful and above all other dragons by using the power they got themselves instead some overpowered ability they were born with, if Issei and Vali respect their decision, then perhaps they won't use it either outside of a life or death situation