- "The life and adventures of Elyo Grivas, First Sword of Braavos."
- ―Davos Seaworth reads the title of Elyo's biography
In the books
In the A Song of Ice and Fire novels there is no character named "Elyo Grivas". The character is possibly named after Elio Garcia, who runs the Westeros.org fansite, and who co-authored The World of Ice & Fire sourcebook along with his partner Linda.
In their video review of the episode, Elio said he doesn't know if the TV writers officially named the character after him. He does frequently exchange e-mails with writer Bryan Cogman to perform some basic, unofficial fact-checks when the writers want to make sure that they are getting some obscure book information correct. Elio therefore speculated that one of the writers might have just subconsciously recalled a similar sounding name to his when they were inventing a new name in the TV series, without deliberately naming the character after him - though there's also the chance that it was a deliberate reference.