Loki was there in his best, of course - mostly because he was dragged by Thor. He did bring a wedding gift, but it's just a box that says 'don't open until married' - any attempts to open it before they're married will fail. If the box is destroyed, it'll just consume itself into a black hole-type thing and reappear completely intact (but leave no damage).
He'll get dragged off to dance with Torunn for a bit and probably end up milling around with some kind of drink - if there's knife throwing, he will absolutely show off, but not act like he's showing off. He's totally showing off.
Hana will also be there at the promise of food! She can probably be found dancing or stuffing her face with donuts and while she doesn't know the couple enough to get them a gift she'll have gotten them a card that might be slightly crinkled from the fact that she bought it like, an hour before the party and wrote it on the back of her MEKA. It'll be parked outside the Meadery.
As for my others like Yuri and Harry, it kinda depends if anyone they know is going!