User blog comment:B214/New anime 2017 discussion blog/@comment-97.86.117.132-20161230234256/@comment-87.8.65.225-20161231003226

yes, it's true. It's DxD EX, you can read it full in english. In this story Issei has more than 20 childrens but in this novel only 10 appear, each one of a different mother: Kurenai (Akeno); Airi (Asia);Zen (Xenovia); Shin (Irina); Helmwige (Rossweisse); Ex (Rias); Robertina (Ravel); Ernestine (Elmenhilde); Shirayuki (Koneko); Kurobara (Kuroka); another one is only mention and you can guess that he is Le Fay's (speaking about him, they say that he refused to wield the holy sword Collbrande to become a wizard).

All of the them are monster (especially in terms of strenght) and Airi and Ex are the strongest ones.

And Gasper became practically Alucard from Hellsing. lol He can literally time travel with his power, no more female dress and always has a creepy grin in his face.lol