User blog comment:B214/Volume 21 info & spoilers/@comment-124.107.216.47-20160616194612

About the New Maous

Millicas and Gasper became Maous in the EX timeline. They were chosen because they became super devils themselves. I don't know about Millicas but at some point before the 30 year gap, Gasper was able to master his Sacred Gear to the point that he can travel back in time and choose those who are not affected by his Sacred Gear.