What about Flygon? If we look closely, it actually has a decent movepool that synergies pretty well with the Dragon's Den field like Fire Punch, Dragon Claw, Dragon Dance, etc... (Because yeah, there's no reason to imagine we'll confront Saphira in a diffrent field from the Dragon's Den, let's be honest). Plus, its double weakness against Ice type would be mitigated thanks to this same field as well. All this combined with its decent speed could make Flygon a potential candidate for Saphira's squad. Kommo-o having an exclusive and powerful Z-Move that boosts all of his stats once used, he could be a guaranteed member of Saphira's team too. Sadly, I don't think we'll see Kingdra as a partner of her in the next episode for two reasons. First, because we already saw Amaria using one in both Blacksteam Factory and Fiore Mansion during the gym battle with her (Depending on the route we've opted for), and secondly because the battlefield of Saphira itself wouldn't play that much in favor of Kingdra's attacks. Just for the reminder, Water and Ice type moves decrease in base power to 0.5x when you fight in the Dragon's Den. It would be weird if we had to deal with this kind of Pokemon in a fire-themed environment while there are better options to look for.
I'm looking forward for this event too! A good idea of scenario to bypass the barrier that separates Labradorra from Calcenon City would be the intervention of Radomus. Maybe he can send us along with other voluntary allies to the other side of PULSE-Mime's roadblock by using the psychic powers of his Pokemon. He already teleported out from 7th Street with Gardevoir shortly after Elias stole the emerald brooch from Luna in Subseven Sanctum, so there might be this remaining possibility where he could repeat this feat and take us to Labradorra thanks to the power of another Pokemon of his team. If that was the case, I hope Charlotte will join us so that she can avenge Saphira who was badly injured at the beginning of episode 18. Additionally, I could not resist to see what her backsprite would look like