Okay so an idea that is super far in the future, especially since it's Gen 9, but as Koraidon and Miraidon spawn in the same spot in Area Zero what if you made them best friends and did a test thing like with the Latis being sisters. They always hang out and have lesbian sex a lot, but both have always wanted a cock and you have the MC give them a Dragon dick like with the Latis, but instead of Salamance maybe Baxcalubir as a point out to it being the Gen 9 Dragon or maybe a Cyclizar as it is their decedent/ancestor. Also, another reason for them being best friends/yuri fuck couple is because Koraidon is a past form of Cyclizar and Miraidon a future version so they could kind of have a best friend bond over their current day decadents/ancestors. Also maybe make them go into the same ball as they can't stand to be without each other. Oh, but as Koridon is a fierce warrior type you would have to fight her if you got her questions of Midiron wrong, but if you get them all right you fuck them both without a fight. Also, their downtime before the ship takes off could be them having the MC choose the "Better Paradox Lizard" like how the birds asked him who had the better tits and the Mews the cuter Mew