Atreus for about half of the night π But then later on he turned back to himself for movie cuddles thank you. He didn't drink a ton but he did eat a lot of Korean bbq especially if people fed him as a baby dragon. (he's terrible at video games so mostly stayed a spectator there)
Ignis likely brought a few platters of something delicious for people to eat! He came ready to be a surprise underdog at Mario Kart and probably did not disappoint. Unless you lost to him and were disappointed. It's the only game he's good at, okay? He's incredibly calm and :| faced the whole time and so expect to be like "who the fuck just-- IGGY" at him and he will quietly :] at you.
Gansey was there with Blue! And lol the rooftop has a garden so he just had to sigh at the plants telling him to fuck off. (He may have had a few drinks because of this but kept wouldn't have gone overboard, or at all if Ronan is there, maybe Blue and him got a hotel room for the night??? plant free!!) He's middling at video games but a team player, and enjoys a good movie time.