User blog comment:Jopjopjop/High School DxD BorN episode 3 review/@comment-149.88.55.35-20150418162228/@comment-1359322-20150418164344

Well technically we need


 * 1) Rating Game > Vritra awakening.
 * 2) Vritra awakening > Help defeat Loki.

So the Rias-Sona Rating Game will definitely happen first. For the others, i'm expecting something like Odin returning exactly on the time when Khaos Brigade attacks during the Rating Game for Rias and Diodora, rescuing them. Then after the incident they prepare for the final battle against Loki.