Dante from Devil May Cry would be an excellent character to pair with Doomguy. Dante is a stylish demon hunter, and when combined with Doomguy's brute force approach, it would create some really cool action scenes. Also, Samus Aran from Metroid could be a good match. Samus' exploration skills and Doomguy's combat abilities could lead to an interesting story, especially if they are in a shared alien - infested environment.
Solid Snake from Metal Gear Solid could be an interesting pairing. Snake's stealth and tactical skills contrasted with Doomguy's all - out - attack style would make for a unique story. And then there's Geralt of Rivia from The Witcher. Geralt's knowledge of monsters and his use of magic, combined with Doomguy's physical prowess, could result in a very engaging crossover fanfiction.
Gintoki from 'Gintama' could be paired with Shizuo. Gintoki's laid - back yet strong - willed personality next to Shizuo's short - tempered and powerful nature would result in some hilarious and action - filled interactions. And Spike Spiegel from 'Cowboy Bebop' could also be a great partner for Shizuo in a crossover. The cool and collected Spike next to the hot - headed Shizuo would make for an interesting character study and some great action sequences.
In a crossover with One Piece, Luffy would be an interesting match for Sakura. Luffy's carefree but determined nature along with his stretchy powers could work well with Sakura's more serious and medical - based abilities. They could embark on a journey together in the crossover, facing various challenges and making new friends along the way.
In crossover fanfiction, Luke Skywalker would be an excellent character to pair with Darth Revan. Luke's journey from a farm boy to a Jedi Master could contrast with Revan's fall and redemption. Another good choice could be Gandalf from The Lord of the Rings. The clash between Gandalf's wisdom and Revan's Sith - influenced knowledge would be interesting. Also, Shepard from Mass Effect could be a great pairing. Their different approaches to leadership and combat would create an engaging story.
Tatsumi from 'Akame ga Kill!' would be a great pair. Tatsumi is a fighter who has a strong sense of justice, and his interaction with Kaneki, who has his own moral struggles as a ghoul, could create an interesting dynamic. They could fight together against common enemies in a crossover world.
Jack O'Neill from Stargate could be an interesting character to pair with Duncan MacLeod from Highlander. Jack's military experience and sense of humor would contrast well with Duncan's noble and sometimes brooding nature. Another good pair could be Daniel Jackson and Methos. Daniel's thirst for knowledge and Methos' ancient wisdom would make for great interactions.
Trunks is another good option. His time - traveling experience and sword - fighting skills could add a new dimension to the crossover. He and Xeno Goku could work together to prevent disasters in different timelines.
In a crossover with the Vampire Diaries, Damon Salvatore could be a great character to pair Kol with. Both are complex and somewhat morally ambiguous vampires. They could have some intense power struggles and also moments of begrudging respect. Another good pairing would be with Bonnie Bennett. Kol's powerful vampire magic and Bonnie's witch powers could create a really interesting dynamic, either as allies or enemies.
Xander and Harry would be an obvious and great pair. They both have a sense of heroism and a willingness to fight against evil. Xander's more laid - back and humorous nature could balance out Harry's sometimes brooding personality. Another good pairing could be Xander and Hermione. Xander might be in awe of Hermione's vast knowledge, and Hermione could be intrigued by Xander's different way of approaching problems.
Issei would be a great choice as he is from the same universe and has a strong connection with Rias already. Their relationship can be further explored in a crossover, especially if they are facing new and different challenges together.
Goku is a great character to pair with Beerus. Their relationship in the original series is full of tension and mutual respect. In fanfiction, they could have all sorts of adventures together, like exploring new galaxies or training in unique ways.