Terezi Pyrope and Black Widow. Terezi's skills as a seer and her somewhat unorthodox way of thinking would pair well with Black Widow's stealth and strategic mind. They could work together on espionage - like missions, with Terezi using her powers to predict the enemy's moves and Black Widow executing the plans.
John Egbert and Spider - Man could be an interesting pairing. John's ability to manipulate wind and his generally positive attitude could contrast well with Spider - Man's quippy and more street - level heroics.
Frisk and Dave Strider would be an interesting pairing. Frisk is all about kindness and determination in Undertale, while Dave is this cool, sarcastic guy from Homestuck. Their different personalities could lead to some really fun interactions, like Dave trying to be all cool while Frisk just goes about their business of being kind to everyone.
A good plot could involve a villain from the Homestuck universe creating chaos in the Avengers' world. The Homestuck characters come to help, but there are misunderstandings at first between them and the Avengers. However, as they start to understand each other's powers and motives, they form a strong alliance to defeat the villain.
I think John Egbert from Homestuck and Bob the Tomato from Veggietales would be really interesting. John is this really optimistic and kind of goofy character, and Bob is always so level - headed and full of wisdom. Their interactions could be really fun, like John trying to understand Bob's simple but profound view on life, and Bob trying to keep up with John's wild ideas.
Russia from Hetalia and Kanaya from Homestuck could be a really unique pairing. Russia has his own mysterious and somewhat intimidating aura, and Kanaya is very poised and has her own set of skills, especially when it comes to fashion and fighting. Their interactions could be quite interesting, like Russia showing Kanaya some of his traditional Russian crafts and Kanaya showing Russia how to make some really cool Homestuck - inspired outfits. Additionally, China from Hetalia and Jade from Homestuck could be a great pair. China with his long history and Jade with her connection to nature and her rather innocent yet powerful nature could create some really engaging storylines.
Definitely Naruto and Hulk. Just imagine Naruto trying to calm down the Hulk when he's angry. It would be hilarious. And on a more serious note, Naruto's positive energy might have an effect on the Hulk. Also, Sakura and Captain America. Sakura is a strong - willed and powerful female character, and Captain America is a symbol of leadership and justice. They could bond over their shared values and exchange fighting strategies.
Sam Winchester and Bruce Banner would be an amazing pairing. Sam is highly intelligent and well - read, and Bruce is a brilliant scientist. They could bond over their knowledge and maybe even find a way to control the Hulk better. Also, Natasha Romanoff and Charlie Bradbury would be a cool pair. They're both strong, independent women with a lot of skills. Natasha could teach Charlie some combat moves, and Charlie could introduce Natasha to some cool geeky stuff like LARPing.
Another interesting pairing would be Captain America and Oliver Queen. Both are leaders with a strong sense of justice. They could have some great discussions about what it means to be a hero and how to lead a team. And when it comes to fighting, they could show off their different combat styles, with Cap's military - trained moves and Oliver's acrobatic and archery - based fighting.
Hawkeye and Sasuke would make a cool pairing. They are both very skilled in ranged combat. Hawkeye could learn some of Sasuke's Sharingan - enhanced archery skills, and Sasuke could be interested in Hawkeye's high - tech arrows. Also, Iron Man and Kakashi would be an interesting match. Iron Man's love for technology and Kakashi's use of Sharingan - based tech like his Ninja Hound summons could lead to some great interactions. They could even collaborate on creating new gadgets for both universes.
I think Harry Potter and Captain America would make a great pairing. Harry has a strong sense of justice and leadership within the wizarding world, and Captain America has similar qualities in the superhero world. They could exchange ideas about leading their respective teams and learn from each other's experiences in fighting evil.
Definitely Harry Potter and Iron Man. Harry has his quick thinking and strong moral compass from growing up in the wizarding world, and Iron Man has his technological genius and sarcastic charm. They could bounce ideas off each other, with Harry explaining the intricacies of magic and Tony trying to find a scientific explanation for it. Maybe Tony could even create some gadgets to work with magic, like a device that can detect hidden magical objects.