I certainly hope Julias team in Ep15 isn't the one she uses against normal trainers now lol. Otherwise no one is getting badges.
You know, Sirius has been in so man battles under different circumstances, its kinda hard to gauge his power. In the beginning he took on Florina and Julia, and if they were using serious teams, not gym teams, that means he was already really tough. Then we fight him in either Yureu or the Tanzan Cove. In both cases he team doesn't seem too strong. But both times he was hindered. Yureu we had Cain team up with us so maybe they lowered the levels of his pokes to represent that he was at a disadvantage two vs one. In Tanzan he claims his pokes were already weakened by Sapphira. So, it seems as though we've never really had a serious (lol) battle with him.