[Parousia]

Originally Posted by belatkuro

No, not really. There's a separate mention of KYH but this seems to be referring to a different one.

Spoiler for vol19 short synopsis rough translation:

Before KYH graduates, to reach the end of the Accelerated World, Haru swore to challenge the Imperial Palace together with Sky Raker. And there appears the Black Swordsman?!

Ok that's something more convincing, well try to read some of the posts before and you'll find a theory that connects the synopsis to SAO.