Rayleigh isn't a character I recognize from any major series off the top of my head, but the name makes me think of two possibilities. First, there's Rayleigh from 'One Piece,' the legendary pirate known as the 'Dark King' and former right-hand man of Gol D. Roger. If that's the one, then the author is Eiichiro Oda, the mastermind behind the whole 'One Piece' universe. Oda's world-building is insane—every character feels alive, and Rayleigh’s wisdom and strength make him a fan favorite.
Another Rayleigh that comes to mind is from sci-fi or fantasy novels, though I can’t pinpoint a specific book. If it’s a lesser-known series, it might take some digging. But if we’re talking 'One Piece,' Oda’s the guy. His ability to weave backstories into the present narrative is unmatched, and Rayleigh’s role as Roger’s former first mate adds so much depth to the lore.