User blog comment:B214/Volume 23 discussion blog/@comment-82.178.103.238-20170802205707/@comment-31137559-20170803195234

Riser looks like he's in his early twenties but I'm not so sure but he most likely is as he is referred to as a young Rating Games competitor. He might be early twenties or mid-twenties.

Sairaorg I feel is a year older than Rias. Just my hunch.

Cao Cao I feel is the same age as Rias. And Strada said he was about 20 at the moment. And right now if he's the same age as Rias that would make him 18/19 at the moment.