User blog comment:Crimson and Darkness/Volume 25 discussion blog/@comment-34061653-20181013135327/@comment-2601:87:8300:20D0:E8A8:69EB:673C:BCD6-20181014135446

The countdown is 8, so maybe 8 minutes. You also have to remember we don't know what kind of game it would be. It could be like that battle with Sona where no destroying things or maybe dice roll. It could also be something we having seen so far. My guess that it would be something that Rias has an advantage in but still loses in the end.