User blog comment:B214/Volume 23 discussion blog/@comment-1884090-20170408001538/@comment-1359322-20170410093344

Being able to recognise talent is meaningless if you can't even find talented people in the first place. So Rias' luck is what made Ise and the others become under her. Sona could've been the one to reincarnate Ise too but it ended up being Rias, so luck is a factor.