Without a doubt, CD Projekt Red's Cyberpunk 2077 had one of the more impressive presentations with its in-engine cinematic trailer at E3 2018. Notably, the game is constantly discussed in conjunction with the developer's Witcher 3, wherein it has been revealed that the futuristic role-playing title approaches romance in a more diverse way than The Witcher 3.
However, one fan by the name of Tolkfan decided that there needed to be more of a crossover between the two titles and use Geralt's adopted daughter Ciri to narrate the Cyberpunk 2077 reveal trailer. As seen below, a voiceover of Ciri has been applied to the trailer, with the narration coming from a discussion between Ciri and Geralt in The Witcher 3.
Interestingly, this crossover makes a lot of sense, in terms of Ciri's powers and her dialogue. Ciri's description of a universe she visited, as crossing dimensions and worlds is one of her powers, fits oddly enough with the world of Night City. Telling Geralt he wouldn't believe her, Ciri describes a world with "houses of glass," "metal in their heads," and "flying ships." Check it out below:
Better yet, her description of the world syncs well with the actual trailer, which may be a supporting factor in the rising number of CD Projekt Red fans who believe Ciri will cameo in the game. The creator of this video even stated that there would be "riots" if she did not, in fact, appear somehow. Of everything that we have learned about Cyberpunk 2077, however, Ciri is not even mentioned.
Of course, a Ciri cameo or Easter egg is likely something CD Projekt Red would keep stashed away, especially considering the game could still be years from release. Still, it has been revealed that the game is targeting a current generation launch, but it remains to be seen if this proves to be true or if the game is delayed until next-generation. Regardless, when the game does release, fans will likely try to hunt down the Witcher's adopted daughter.
Cyberpunk 2077 has no release date.