User blog comment:B214/Talk About What You Want! 3/@comment-27711757-20160211034933/@comment-73.160.58.215-20160211205129

Yes, that is from an official artbook, as Gary said. The bottom art is Azazel's Downfall Dragon Spear / Another Armor. The rest should also be the same as what Gary stated (though I'm not 100% sure about Saji). Whatever the Spanish site might've said about it being Issei's Diabolos Dragon form is total bull.