User blog comment:Crimson and Darkness/Volume 25 discussion blog/@comment-34061653-20180506195121/@comment-28884330-20180506230733

Xenovia doesn't have the means to fight gods. She can keep up a defensive struggle and that's about it. After all, Apollon when he simply got annoyed with her could simply trap her and move away. The only reason Xenovia could last as long as she did is because of the hax Excalibur sheath that makes her invulnerable. If she was god class then they wouldn't have lost against Dulio's team. She couldn't even put Nero down for good. Strada could, for example, cut Xenovia's swords to incapacitate her without having to retire her, or Lint could deal with her and keep her busy. Xenovia doesn't have to be retired or damaged to be incapacitated until the game ends.

I have no idea how much time stops Rias can do before she runs out of steam (it wasn't even stated how many times she stopped Fenrir, after all), and considering that my hypothesis doesn't rely on her current strength but on the potential level she might acquire by the time her team confronts Issei's, I can't give an answer on whether she can stop Ddraig 140 times. I'm not saying that team Rias WILL beat Ddraig and Issei's team, but she certainly has more chances than what you're suggesting.