Diego appears the same in both Chapter 1 and Chapter 2. He has black messy hair, with bangs and green eyes. Diego also has what looks like an eagle tattoo on his neck, as well as some scars on his face.
He wears a black top that has an oversized neck, and slopes down towards his left hip exposing most of his stomach, except for where there are two straps that wrap around. He also has black armbands that extend to cover a majority of his arms. He also wears maghony pants, with matching belts.
Because he is Adeshian, Diego tends to be flirtatious towards most of the women in the game, namely Aida and Sky. Diego can be completely heartless at times, especially in the earlier portions of the game.
Diego served as a plant in The Knight Order under the pseudonym "Cain." He was Jace's partner, or "brother," in the Order. Jace was tricked into thinking that his brother was killed by an "arrow to the head" because of a hallucination potion.
As of chapter two, he is skilled with his dagger. In some scenes, he is shown with a bow and arrow.
- Jace: Diego had been Jace's "brother" when he was pretending to be "Cain" in The Knights Order. He had actually drugged Jace with a hallucination potion so he would think he was seeing "Cain" dead.
- Sky: At first, Sky had harsh feelings toward Diego, because he was the one who ordered her father's death. Throughout chapter 3, the relationship seems to improve. In Adeshia (Chapter 3), Sky confesses to kissing Diego at Tillie's wedding, when Diego carried her up to her room (she was drunk). Aida isn't happy with the fact that her best friend is in love with the murderer.
- Aida: He wanted to see her nude in Chapter 3.
- Diego is actually the one who sold out The Knight Order.
- Rinmaru stated that he's bisexual.
- His birthday is November 10th
- "Forgive me, our way of inviting people isn't exactly subtle..." -Diego to Aida
- Diego: "Beautiful and strong. Join me." Aida: "You want me to join the Eagles?" Diego: "No, I meant in my quarters but sure the Eagles too."
- "You should have seen your face. It was hilarious." -Diego to Jace about watching him hallucinate Cain's death.
- 'I'm helping you out because you are the only person who can stop your brother. But that doesn't give you the right to meddle in my private affairs. She is not your child'. -Diego to Aida about Sky