The lack of a real really masculine character in the video game Genshin Impact is disconcerting. That is why the best candidate for a cross-over character would be the Heavy Weapons Guy from the video game Team Fortress 2 by Valve. 

He would make a very cool addition to the roster of unique characters in Genshin Impact. He could be a very cool Geo tank character. As well as adding some variety I think Genshin Impact very much needs.