Diego has brown eyes, short, black hair and tan skin. He wears a short sleeved purple checked shirt.
In Book 2, his hair is much longer and he has a moustache, beard, and goatee.
Diego loves parties and is a huge fan of pop culture. Throughout the story, he is constantly making references to various movies and TV shows. He is shown to be very kind and worries about others. He is also probably homosexual or bisexual as in Chapter 14 he tells Your Character about having a crush on one of the guys (Sean, Jake, Raj, Craig). His file in Rourke's database says that he hides certain parts of his personality from his more conservative family.
In Book 2, Chapter 2, it's revealed that he's been living among the Watchers during the last six months.
Diego is Your Character's best friend. Diego also tends to confide his feelings and secrets in Your Character, such as his crush on one of the other male members of the group in Chapter 14. He seems impressed when you think like a detective, such as correctly guessing that Estela being on the plane is suspicious and guessing that the computer password is Zodiac.
In Book 1 Chapter 16, he sacrifices himself to the Vaanti, leaving you riddled with guilt to the point where you hallucinate.
When they are finally reunited in Book 2 Chapter 3, he says he always knew you would come back for him.
Diego helped teach Varynn how to speak English. You can choose to help them get together. Depending on your choices, they could kiss on New Year's Eve.
- His Hadean Zodiac sign is Canis, the Dog.
- Of the three potential group members left behind in the final chapter, only Diego's disappearance is non-negotiable, as either Raj or Grace can be saved, whereas Diego is pulled out of the time bubble by a Watcher.
- Jake calls him "Pop Culture Petey" because of his obsession with Movies.
- His Catalyst Idol shows him trying to save Varynn in the observatory but both of them are killed by IRIS when she activates machine guns.