In my opinion, it would probably be Kurt from Glee and Darren Criss (who is associated with Starkid). Kurt is very fashion - forward and has a strong passion for performing arts. Darren Criss is known for his incredible talent in Starkid productions. Their shared love for music and the stage would likely draw them together first.
It could be Blaine from Glee and Joey Richter from Starkid. Blaine is charming and confident in his performances, and Joey Richter has a great on - stage presence in Starkid shows. They might meet at a big musical event that somehow bridges the two universes. They could start off with some friendly competition in a singing duel and then gradually become friends as they realize they can learn from each other.
I think Quinn and Black Widow would be an interesting pair. Quinn is used to being in a position of power and popularity in the Glee club, and Black Widow is a strong female character in the Avengers. They could have some really cool exchanges about strength and femininity.
It could be Zane from Ninjago and Trixie from Slugterra. Zane is very logical and has a lot of knowledge about technology and combat strategies. Trixie is smart and resourceful in the world of Slugterra. They might cross paths while investigating some strange occurrences that seem to be related to the crossover. Their initial meeting would probably involve a lot of questions and mutual curiosity as they try to figure out where the other is from and what they are doing in this new, combined situation.
Mercy from Overwatch and the Medic from TF2 could be the first to interact. Given their roles as healers, they would likely be interested in each other's medical techniques. They might start by comparing notes on how to heal their comrades more effectively, and this could lead to a deeper understanding and cooperation between the two groups.
Probably Leonardo from the Turtles and Freddy Fazbear. Leonardo is the leader, so he would likely be the first to step forward and assess the situation when they encounter the FNAF animatronics. Freddy, being the main animatronic, would also be in the forefront. Their personalities are quite different, with Leonardo being more disciplined and Freddy having a more mysterious and somewhat menacing presence. Their first interaction could be a tense stand - off as they try to figure out each other's intentions.
Probably Bloom from the Winx Club and Master Chief from Halo. Bloom is the main character in the Winx Club, very powerful and often takes the lead in dangerous situations. Master Chief is the iconic figure in Halo. Their paths might cross first because they both have a strong sense of duty and leadership. They would be likely to recognize each other's capabilities quickly and start to work together, like when facing an initial threat that appears in both of their worlds.
Probably Wolverine and Spiderman. Wolverine is often on the front lines in X - Men stories, and his no - nonsense attitude would contrast well with Spiderman's quippy nature. They might meet when investigating a strange occurrence in New York that involves both mutants and non - mutants.
Definitely Harry Potter and Finn Hudson. Harry is the hero in the wizarding world, and Finn is a key figure in the Glee club. They could bond over their leadership roles. Harry could teach Finn some magic tricks, and Finn could show Harry how to be more confident while performing in front of a large audience.
I think Sakura from Naruto and Stella from Winx could interact a lot. Sakura is a strong - willed and intelligent kunoichi, and Stella is a confident and powerful fairy. They could have some really interesting conversations about their respective worlds, like comparing the medical ninjutsu in Naruto's world to the healing magic in the Winx world. And they might also get into some friendly rivalries while training together.
Definitely Ruby Rose and Master Chief. Ruby is the main character in RWBY, full of energy and determination. Master Chief is a well - known and iconic figure in Halo. Their different personalities and combat styles would create an interesting dynamic. Ruby's quick - thinking and agility could pair well with Master Chief's stoic and strategic approach in battles.
Bloom and Iron Man could be likely to interact. Bloom is a powerful fairy with strong leadership qualities, and Iron Man is a genius inventor and leader in the MCU. They could both exchange ideas about leadership and power, and maybe Bloom could teach Tony a thing or two about magic. Another pair could be Stella and Thor. Stella loves fashion and luxury, and Thor is from a royal background in Asgard, so they could bond over their love for grandeur.