Shepard, being a natural leader in Mass Effect, would probably try to take charge in any joint operations with Stargate characters. However, some of the more experienced Stargate commanders might not be so quick to follow. This could lead to some power struggles at first, but eventually, they would learn to respect each other's skills and work together more effectively.
The Asari from Mass Effect would be intrigued by the Ancient technology in Stargate. Their natural curiosity and long lifespan would make them eager to study it. Meanwhile, the Goa'uld from Stargate might see the various species in Mass Effect as potential hosts or slaves, which would obviously lead to conflict. But the more moral characters from Stargate would oppose this and try to protect the Mass Effect races.
If Tali met Naruto, she would be amazed at his ninja skills. Tali is used to advanced technology, but Naruto's physical abilities and unique jutsus would be a whole new concept for her. Naruto would be interested in Tali's engineering skills and might ask her to help create some new ninja tools. Garrus would probably respect Naruto's combat skills and see him as a valuable ally in a fight. And Naruto would be drawn to Garrus's sense of justice.
The characters from Call of Duty, being mostly military - based, would likely be initially cautious and strategic when interacting with Mass Effect characters. For example, Captain Price might approach Shepard with a sense of respect but also wariness. He would be interested in Shepard's leadership skills and how they handle the diverse alien races. Meanwhile, Shepard would probably be curious about the more 'grounded' combat tactics of the Call of Duty soldiers.
If a character like Miranda Lawson from Mass Effect met Mercer, she would probably be fascinated by his biological makeup. She might try to analyze him from a scientific perspective, which Mercer may or may not tolerate. And when it comes to combat, Mercer could provide a new and unexpected element to the fight. For example, he could use his shape - shifting to surprise enemies while the Mass Effect characters use their biotics and tech. Also, the loyalty and morality of the Mass Effect characters could have an impact on Mercer. He might start to question his own actions and motives in the face of their strong beliefs.
Noble Six would probably be a bit of an enigma to the Mass Effect characters at first. They might be cautious around Six because of their different appearance and unknown abilities. But over time, they could learn to trust each other.
The more stoic Gundam characters like Amuro might initially be reserved in their interactions. But as they face common threats, they would start to open up and share their knowledge. In contrast, the more outgoing Mass Effect characters like Garrus might be quick to befriend the Gundam pilots and try to get them involved in their adventures right away. They could bond over their shared love for combat and protecting the innocent.
The Krogan from Mass Effect and the Berserkers from Gears of War could have a really intense interaction. The Krogan are known for their brute strength and warrior culture. The Berserkers are these large, powerful and somewhat mindless (in a combat sense) enemies. The Krogan might see the Berserkers as a worthy challenge and try to engage them in combat on their own terms. This could lead to some epic battles where the Krogan's natural strength and regenerative abilities are put to the test against the Berserkers' brute force.
A rather unexpected but potentially great pairing could be Ashley Williams and Vala Mal Doran. Ashley is a tough and no - nonsense soldier in Mass Effect, and Vala is a wily and resourceful adventurer in Stargate. They could get into all sorts of scrapes together and use their different skills to get out of them. On the other hand, Kaidan Alenko and Jonas Quinn could be paired. Kaidan has biotic powers in Mass Effect, and Jonas has his own unique abilities in Stargate. They could explore how their powers might interact or complement each other in different situations.
Shepard from Mass Effect might initially be very cautious around the Crysis characters. Given Shepard's military background, they would likely be sizing up the situation and the capabilities of the Crysis characters. For example, if faced with a character in a nanosuit, Shepard would be curious about its technology. Meanwhile, the Crysis characters would probably be in awe of the diverse alien races in Mass Effect. A character from Crysis might be shocked to see a Krogan for the first time and initially be on guard.
Well, Spencer Reid from Criminal Minds would probably be fascinated by the technology from the Stargate universe. He'd be constantly asking questions and trying to understand the scientific principles behind it. Meanwhile, Colonel Jack O'Neill from Stargate might find Reid a bit of an oddball at first, but would grow to respect his intelligence.
The characters would interact in very interesting ways. For instance, Jack O'Neill from Stargate SG1 is a military man with a sarcastic sense of humor. He would probably find Gibbs from NCIS to be a kindred spirit in terms of military discipline, but their leadership styles might clash at times. Gibbs is more about leading by example and getting his hands dirty in investigations, while O'Neill has to deal with leading a team on dangerous off - world missions.