User blog comment:B214/High School DxD EX/@comment-82.60.176.170-20151228181216

So the 10th son sent into the present is Issei and Le Fay's son since Robertina said that he choose to be a wizard rather than choose to use the Holy King Sword Collbrande (and since that sword belong to Pendragon House and the current wielder is Arthur, Le Fay's brother.....