Another likely pair to interact first could be Stella from the Winx Club and the Arbiter from Halo. Stella is very confident and has a strong personality. The Arbiter is also a respected figure in the Halo universe. Stella's bright and flashy powers might catch the Arbiter's attention, and he might approach her out of curiosity. Stella, being the social one among the Winx, would be open to talking to him, and they could start to exchange information about their respective universes.
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.
I think it could be Tecna from the Winx Club and Cortana from Halo. Tecna is the tech - savvy fairy in the Winx Club, and Cortana is an AI with vast knowledge. They would be interested in each other's technological or knowledge - based abilities. Tecna might be fascinated by Cortana's programming and intelligence, while Cortana could be intrigued by Tecna's use of magic in a technological - like way. Their interaction could start as a mutual exploration of each other's 'worlds' of knowledge.
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.
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.
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.
Mercy from Overwatch and Cortana from Halo might have an interesting interaction. Mercy is a healer and Cortana is an AI. They could discuss the ethics of artificial intelligence and how Mercy's healing technology could potentially be applied in the Halo universe, or vice versa how Cortana's knowledge could enhance Overwatch's medical technology.
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.
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.
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.
The Winx girls, being used to a more fairy - like magic, would be curious about the wand - based magic of the Harry Potter characters. Bloom might ask Harry to show her how to cast a Patronus charm. The Hogwarts students, on the other hand, would be in awe of the Winx's transformation abilities. Hermione would probably be eager to study the different types of magic the Winx use and write it all down in her notebook.
Musa and Raven Queen might get along well. Musa is very in touch with her emotions through her music in the Winx Club, and Raven Queen is constantly dealing with her own inner turmoil in Ever After High. They could bond over their shared experiences of dealing with complex feelings and not always fitting in with the norm.