Peter is dressed as Flynn Rider, while Sabrina is dressed as Rapunzel. They are adorable and disgusting in their adorableness. Peter walks around the whole night with an "I can't believe how lucky I am" look on his face.
Steve is dressed as Derek. XD He's wearing tight, dark jeans, a deep wine red henley with thumb holes, and a black leather jacket. He hasn't shaved in a few days. It's a little silly, but with Derek by his side holding his hand, he feels a little more secure.
Henry is dressed as a pirate with a hook for his hand... (This isn't Hook from Once Upon a Time, though the resemblance is striking.) His outfit comes complete with a metal hook, and heavy eyeliner.
Kate arrived in a smoking hot black dress, wearing a cat-eye mask that reminded her a lot of her Hawkeye mask from her own world. She drank a few glasses of whatever alcohol was available, and then danced. And danced. And danced.
Cath wore black and red, along with a long, red cloak that reached the floor. She wasn't sure about masquerades or Halloween, but she figured this would be an appropriate costume for the occasion. The whole time she was at the party, she was worried she'd chosen wrong.
Yelena's curves were kicking in her cat burglar costume... which might be familiar to any bats in the room. This is purely coincidental, I swear. ;)