My knowledge of Castlevania: Moonlight Rhapsody is limited. That said, I have some headcanons.
It can make sense that there's a character named Elvis if he was given the nickname by an English-speaking time traveler whose home time was in the famous personality's time period.
Reynolds goes by a single name, and if he has time travel access, it makes sense he's hiding his last name.
Maria Renard is at the bar in Reynolds' Mobile Base, 1870. The phonograph on the bar was not yet developed in 1870. Yoko Belnades and Soma Cruz from the mid-2030s are also playable characters (if you can actually play it). Time travel established.
Quoting Reynolds' page at https://castlevania.fandom.com/wiki/Reynolds , he "is the president of the Demon Hunter Guild and a point of contact between the guild and other forces opposed to Dracula."
Reynolds: Of course, it took years to improve the ancient magic tool,
Key word, magic. Reynolds has been gathering magic users. Logically he would be a sorcerer.
Reynolds: ... After decades of preparation, the Demon Hunter Guild has finally arrived at this moment!
( ... Since the appearance of Castlevania, he has been contacting various forces to join the battle.)
The parentheses above is part of the game dialogue. https://castlevania.fandom.com/wiki/Reynolds/Dialogue
Decades of preparation. Given Reynolds' is, ballpark, 33 years old, did he start this project?
Could Reynolds be the son of Jonathan Morris (see looks below) and Charlotte (sorceress)?
He would have listened to Elvis Presley growing up. He probably plays Elvis' music on the phonograph at the bar at the Mobile Base in the 1860s.
He would have been part of the Battle of 1999. Who else knows about that event? Julius Belmont. Who are playable characters in this game? Alucard, Yoko Belnades and Soma Cruz, who are with Julius when he gets his memories back.
Would a son of Jonathan Morris call an orphaned, straight arrow, French dhamphir boy named Ives (sounds like Eve), Elvis?
Red+blue=purple?
All said, it's of note that another blue, sanpaku-eyed, narrow-chinned, generally straight-haired magician named an English version of Rinaldo is at the forge.
And that Rinaldo happens to resemble 1999-era (1960s more like) Jonathan.
I'm adding additional photos so Jonathan (non-canon, along with other non-canon things in this post) and Juste's red coats and the Magic Gauntlet made by Rinaldo can be compared.
