A plot could involve a Mass Relay being found in a hidden, ancient tomb that Lara Croft is exploring. This Mass Relay is malfunctioning and causing strange disruptions in both universes. Shepard's crew and Lara must work together to repair it. Along the way, they share their skills and knowledge. Lara shows Shepard how to handle ancient traps and he teaches her about space - faring technology and combat tactics specific to the Mass Effect universe.
One possible plot could be Lara Croft discovers a Prothean artifact during one of her adventures. This artifact has a connection to the Mass Effect universe, perhaps it contains data about the Reapers. She teams up with Commander Shepard to figure out how to use this information to stop the Reapers or some other threat that is starting to cross over from the Mass Effect universe into her world.
Lara Croft and Commander Shepard would be an obvious and very interesting pairing. They are both strong leaders and adventurers. Lara's knowledge of ancient civilizations and her survival skills could complement Shepard's military leadership and combat experience in space battles. They could learn a great deal from each other.
Well, perhaps in the fanfiction, Lara Croft is exploring an uncharted planet when she stumbles upon a Halo ring. This attracts the attention of the Covenant, and Master Chief arrives to deal with the situation. At first, there's some tension between them as they come from different worlds and ways of doing things. But as they start to understand each other's motives and skills, they combine Lara's knowledge of ancient mysteries and Master Chief's combat expertise to fight the Covenant and figure out the secrets of the Halo ring.
One idea could be that Lara Croft is exploring an ancient tomb and stumbles upon a hidden Umbrella Corporation facility. She discovers that they were experimenting with some sort of ancient virus that was sealed in the tomb long ago. The T - virus has escaped and is starting to mutate the local wildlife and some of the tomb's guardians. Lara has to team up with a Resident Evil character, like Jill Valentine, to stop the virus from spreading further and also figure out how to deal with the newly awakened threats in the tomb.
A possible plot could be that there is a powerful and mysterious force that is causing chaos in different parts of the world. Both Lara Croft and Wonder Woman are independently investigating it. Eventually, they meet and decide to team up. They travel to different locations, from ancient ruins to modern cities. During their journey, they exchange stories about their past adventures and develop a mutual respect. They then use their combined knowledge and powers to track down the source of the chaos, which turns out to be a mad scientist who wants to use the power of the gods for his own gain.
Well, one possibility could be that Naruto, with his ninja skills, teams up with Lara Croft in a tomb raiding adventure. Maybe they are searching for a powerful artifact that has ties to both their worlds. Naruto could use his shadow clones to help in exploring different areas of the tomb at the same time, while Lara uses her knowledge of ancient languages and traps.
Well, it could be about Ben using his alien forms to fight alongside the Mass Effect characters against a common enemy like the Reapers. Maybe his Four Arms form could be used for brute strength in hand - to - hand combat with the husks.
A possible plot is that the Reapers from Mass Effect start invading the world of My Hero Academia. The heroes would have to use their quirks in new and creative ways to fight off these giant mechanical threats. Maybe All Might could inspire the Mass Effect heroes with his unwavering spirit, while Shepard could teach the My Hero Academia characters about advanced military tactics.
One possibility could be that the races from Mass Effect come to the now - abandoned Earth and start exploring the ruins. They might find remnants of human technology and culture that could change their understanding of the humans. For example, they could discover old military bases with advanced weaponry blueprints that could be used in their own conflicts.
Well, the plot could involve Noble Six being somehow transported into the Mass Effect universe. Maybe they could team up with Shepard. Noble Six's combat skills would be a great asset in the fight against the Reapers.
Another plot could be set in a world where the myths and legends of both Uncharted and Tomb Raider exist simultaneously. Nathan and Lara are called upon by a secret society to retrieve an item that can save the world from a cataclysmic event. Along the way, they discover that their families' pasts are intertwined with the mystery of this item, leading to some emotional revelations as well as exciting adventures through jungles, tombs, and ancient ruins.